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1.
Article in English | MEDLINE | ID: mdl-34003739

ABSTRACT

A phytoplasma was initially detected in Dypsis poivriana by nested and real-time PCR from the botanical gardens in Cairns, Queensland, Australia in 2017. Further surveys in the Cairns region identified phytoplasma infections in eight additional dying ornamental palm species (Euterpe precatoria, Cocos nucifera, Verschaffeltia splendida, Brassiophoenix drymophloeodes, Burretiokentia hapala, Cyrtostachys renda, Reinhardtia gracilis, Carpoxylon macrospermum), a Phoenix species, a Euterpe species and two native palms (Archontophoenix alexandrae). Analysis of 16S rRNA gene sequences showed that this phytoplasma is distinct as it shared less than 97.5 % similarity with all other 'Candidatus Phytoplasma' species. At 96.3 % similarity, the most closely related formally described member of the provisional 'Ca. Phytoplasma' genus was 'Ca. Phytoplasma noviguineense', a novel taxon from the island of New Guinea found in monocotyledonous plants. It was slightly more closely related (96.6-96.8 %) to four palm-infecting strains from the Americas, which belong to strain group 16SrIV and which have not been assigned to a formal 'Candidatus Phytoplasma' species taxon. Phylogenetic analysis of the 16S rRNA gene and ribosomal protein genes of the phytoplasma isolate from a dying coconut palm revealed that the phytoplasma represented a distinct lineage within the phytoplasma clade. As the nucleotide identity with other phytoplasmas is less than 97.5 % and the phylogenetic analyses show that it is distinct, a novel taxon 'Candidatus Phytoplasma dypsidis' is proposed for the phytoplasma found in Australia. Strain RID7692 (GenBank accession no. MT536195) is the reference strain. The impact and preliminary aspects of the epidemiology of the disease outbreak associated with this novel taxon are described.


Subject(s)
Arecaceae/microbiology , Cocos/microbiology , Phylogeny , Phytoplasma/classification , Plant Diseases/microbiology , Bacterial Typing Techniques , Base Composition , DNA, Bacterial/genetics , Fatty Acids/chemistry , Phytoplasma/isolation & purification , Queensland , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
2.
Article in English | MEDLINE | ID: mdl-34499595

ABSTRACT

A novel cellulase-producing actinomycete, designated strain NEAU-H7T, was isolated from coconut palm rhizosphere soil collected from Wenchang City, Hainan Province, PR China. A polyphasic taxonomic study was carried out to establish the status of this strain. Results of 16S rRNA gene sequence analysis indicated that strain NEAU-H7T belonged to the genus Actinoplanes, with highest similarity to Actinoplanes hulinensis NEAU-M9T (99.2 % 16S rRNA gene sequence similarity). The diagnostic sugars in cell hydrolysates were determined to be ribose, galactose and mannose. The major fatty acids (>10%) were C16 : 0, C18 : 1 ω9c and C18 : 0. The predominant menaquinones were identified as MK-9(H4) and MK-9(H6). The major polar lipids were phosphatidylethanolamine, phosphatidylinositol and two phosphatidylinositol mannosides. The amino acid of the cell-wall peptidoglycan was determined to be meso-diaminopimelic acid. The DNA G+C content was 71.2 mol%. Phylogenetic analysis using 16S rRNA gene sequences showed that strain NEAU-H7T formed a stable phyletic line with A. hulinensis NEAU-M9T. However, whole-genome phylogeny showed strain NEAU-H7T formed a stable phyletic line with A. hulinensis NEAU-M9T (99.2%), Actinoplanes campanulatus DSM 43148T (98.6%), Actinoplanes capillaceus DSM 44859T (98.3%) and Actinoplanes lobatus DSM 43150T (97.6%). The digital DNA-DNA hybridization (dDDH) results between them were 53.6 (50.9-56.2), 54.1 (51.3-56.9), 53.1 (50.3-55.9) and 52.9 % (50.1-55.6 %), and whole-genome average nucleotide identity (ANI) values between them were 93.7, 93.6, 93.5 and 93.5 %. The low dDDH and ANI values demonstrated that strain NEAU-H7T could be distinguished from its reference strains. Moreover, genomic analysis indicated that the strain NEAU-H7T had the potential to decompose cellulose and produce bioactive compounds. On the basis of morphological, chemotaxonomic and phylogenetic characteristics, strain NEAU-H7T is proposed to represent a novel species of the genus Actinoplanes, with the name Actinoplanes flavus sp. nov. The type strain is NEAU-H7T (=CCTCC AA 2020034T=DSM 112042T).


Subject(s)
Actinoplanes , Cocos/microbiology , Phylogeny , Rhizosphere , Soil Microbiology , Actinoplanes/classification , Actinoplanes/isolation & purification , Bacterial Typing Techniques , Base Composition , Cellulase , China , DNA, Bacterial/genetics , Fatty Acids/chemistry , Phospholipids/chemistry , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Vitamin K 2/analogs & derivatives , Vitamin K 2/chemistry
3.
Int J Syst Evol Microbiol ; 70(5): 3491-3496, 2020 May.
Article in English | MEDLINE | ID: mdl-32374249

ABSTRACT

During studies on the endophytic yeast communities associated with fruits from Vietnam, three fermenting yeast strains were isolated from fruits of the coconut palm (Cocos nucifera). Phylogenetic analysis based on the sequences of the ITS regions and D1/D2 domains of the large subunit rRNA gene showed that these strains represented a single species of the Yamadazyma clade that was distinct from the other related species. The new species represented a basal branch of the clade formed by the Yamadazyma species i.e. Y. insecticola and Y. takamatsuzukensis. Based on the phylogenetic analysis and phenotypic characteristics, the studied strains were assigned to a novel species of the genus Yamadazyma, for which the name Yamadazyma cocois f.a., sp. nov. is proposed. The holotype is VCIM 4241, with the ex-type cultures VTCC 920004=VKM Y-3049=KBP Y-6091 code 17-68. The MycoBank number is MB 834435.


Subject(s)
Cocos/microbiology , Phylogeny , Saccharomycetales/classification , DNA, Fungal/genetics , DNA, Ribosomal Spacer/genetics , Fermentation , Mycological Typing Techniques , Saccharomycetales/isolation & purification , Sequence Analysis, DNA , Vietnam
4.
Mol Biol Rep ; 46(1): 479-488, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30600458

ABSTRACT

The root (wilt) disease caused by phytoplasma (Ca. Phytoplasma) is one of the major and destructive occurs in coconut gardens of Southern India. As this organism could not be cultured in vitro, the early detection in the palm is very much challenging. Hence, proper early diagnosis and inoculum assessment relay mostly on the molecular techniques namely nested and quantitative PCR (qPCR). So, the present study qPCR assay conjugated with TaqMan® probe was developed which is a rapid, sensitive method to detect the phytoplasma. For the study, samples from different parts of infected coconut palms viz., spindle leaflets, roots and the insect vector-leaf hopper (Proutista moesta) were collected and assessed by targeting 16S rRNA gene. Further, nested PCR has been carried out using p1/p7 and fU5/rU3 primers and resulted in the amplification product size of 890 bp. From this amplified product, specifically a target of 69 bp from the 16S rRNA gene region has been detected through primers conjugated with Taqman probe in a step one instrument. The results indicated that the concentration of phytoplasma was more in spindle leaflets (8.9 × 105 g of tissue) followed by roots (7.4 × 105 g of tissue). Thus, a qPCR approach for detection and quantification of coconut phytoplasma was more advantageous than other PCR methods in terms of sensitivity and also reduced risk of cross contamination in the samples. Early diagnosis and quantification will pave way for the healthy coconut saplings selection and management under field conditions.


Subject(s)
Cocos/microbiology , Phytoplasma/genetics , Real-Time Polymerase Chain Reaction/methods , Arecaceae/genetics , Cocos/genetics , DNA Primers , DNA, Bacterial/genetics , India , Phylogeny , Phytoplasma/pathogenicity , Plant Diseases/genetics , Plant Diseases/microbiology , Plant Leaves/genetics , Plant Leaves/microbiology , Plant Roots/genetics , Plant Roots/microbiology , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
5.
Foodborne Pathog Dis ; 16(10): 704-711, 2019 10.
Article in English | MEDLINE | ID: mdl-31135181

ABSTRACT

Bacterial spores are generally more resistant than vegetative bacteria to ultraviolet (UV) inactivation. The UV sensitivity of these spores must be known for implementing UV disinfection of low acid liquid foods. UV inactivation kinetics of bacterial spores in coconut water (CW) and distilled sterile water was studied. Populations of Bacillus cereus and Clostridium sporogenes dormant spores were reduced by more than 5.5 log10 at the UV-C photon fluence of 1142 µE·m-2 and 1919 µE·m-2 respectively. C. sporogenes spores showed higher UV-C resistance than B. cereus, with the photon fluence 300 µE·m-2 required for one log inactivation (D10) and 194 µE·m-2, respectively. No significant difference was observed in D10 values of spores suspended in the two fluid types (p > 0.05). The inactivation kinetics of microorganisms were described by log linear models with low root mean square error and high coefficient of determination (R2 > 0.98). This study clearly demonstrated that high levels of inactivation of bacterial spores can be achieved in CW. The baseline data generated from this study will be used to conduct spore inactivation studies in continuous flow UV systems. Further proliferation of the technology will include conducting extensive pilot studies.


Subject(s)
Bacillus cereus/radiation effects , Clostridium botulinum/radiation effects , Cocos/microbiology , Fruit and Vegetable Juices/microbiology , Ultraviolet Rays , Bacillus cereus/growth & development , Clostridium botulinum/growth & development , Disinfection/methods , Food Contamination/prevention & control , Food Handling/methods , Food Microbiology , Kinetics , Spores, Bacterial/radiation effects
6.
Int J Mol Sci ; 20(10)2019 May 14.
Article in English | MEDLINE | ID: mdl-31091742

ABSTRACT

Ceratocystis paradoxa, the causal agent of stem-bleeding disease of the coconut palm, causes great losses to the global coconut industry. As the mechanism of pathogenicity of C. paradoxa has not been determined, an exogenous gene marker was introduced into the fungus. In this study, pCT74-sGFP, which contains the green fluorescent protein (GFP) gene, and the hygromycin B resistance gene as a selective marker, was used as an expression vector. Several protoplast release buffers were compared to optimize protoplast preparation. The plasmid pCT74-sGFP was successfully transformed into the genome of C. paradoxa, which was verified using polymerase chain reaction and green fluorescence detection. The transformants did not exhibit any obvious differences from the wild-type isolates in terms of growth and morphological characteristics. Pathogenicity tests showed that the transformation process did not alter the virulence of the X-3314 C. paradoxa strain. This is the first report on the polyethylene glycol-mediated transformation of C. paradoxa carrying a 'reporter' gene GFP that was stably and efficiently expressed in the transformants. These findings provide a basis for future functional genomics studies of C. paradoxa and offer a novel opportunity to track the infection process of C. paradoxa.


Subject(s)
Ascomycota/genetics , Gene Transfer Techniques , Ascomycota/pathogenicity , Cocos/microbiology , Genetic Vectors/genetics , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism
7.
Environ Monit Assess ; 191(3): 179, 2019 Feb 22.
Article in English | MEDLINE | ID: mdl-30796607

ABSTRACT

Monitoring of air quality using lichens as bioindicators on the basis of lichen diversity and frequency is limited along rural-urban ecosystems in tropics. This study attempted to assess and correlate the use of corticolous lichens with atmospheric SO2 and NO2 in such an ecosystem in Sabaragamuwa Province in Sri Lanka. Nine sampling locations, each having three subsampling sites with 162 Mangifera indica and Cocos nucifera trees, were selected for the study. The coverage and frequency of lichens found on selected trees were recorded by 400-cm2 grids and identified using taxonomic keys. SO2 and NO2 levels at each site were determined by "Ogawa" passive air samplers. Data of lichen diversity were used to formulate the index of atmospheric purity (IAP). The environmental parameters related to lichen colonization were measured using standard methods. Data were analyzed using MINITAB 17. The mapping of spatial distribution of lichens and air pollutants were done using inverse distance weighting surface interpolation of geographical information system based on IAP values. A negative correlation was observed between IAP and SO2 and NO2 levels. The presence of the genus Pyxine in almost all urban sites indicated that it could be used as a reliable pollutant tolerant indicator in urban ecosystems. In addition, the index-based mapping techniques could be used successfully to see the effect of atmospheric pollution in urban ecosystems. These results conclude that corticolous lichens have the potential to be used as bioindicators of air quality monitoring along rural-urban ecosystems of tropics.


Subject(s)
Air Pollutants/analysis , Air Pollution/analysis , Environmental Biomarkers/physiology , Environmental Monitoring/methods , Lichens/growth & development , Nitrites/analysis , Sulfur Dioxide/analysis , Cocos/microbiology , Ecosystem , Geographic Information Systems , Mangifera/microbiology , Sri Lanka , Trees
8.
MMWR Morb Mortal Wkly Rep ; 67(39): 1098-1100, 2018 Oct 05.
Article in English | MEDLINE | ID: mdl-30286052

ABSTRACT

Foodborne salmonellosis causes an estimated 1 million illnesses and 400 deaths annually in the United States (1). In recent years, salmonellosis outbreaks have been caused by foods not typically associated with Salmonella. On May 2, 2017, PulseNet, CDC's national molecular subtyping network for foodborne disease surveillance, identified a cluster of 14 Salmonella Chailey isolates with a rare pulsed-field gel electrophoresis (PFGE) pattern. On May 29, Canadian health officials informed CDC that they were also investigating a cluster of five Salmonella Chailey infections in British Columbia with the same PFGE pattern. Nineteen cases were identified and investigated by CDC, U.S. state health departments, the Public Health Agency of Canada, and the British Columbia Centre for Disease Control. Isolates from all cases were highly related by whole genome sequencing (WGS). Illness onset dates ranged from March 10 to May 7, 2017. Initial interviews revealed that infected persons consumed various fresh foods and shopped at grocery chain A; focused questionnaires identified precut coconut pieces from grocery chain A as a common vehicle. The Canadian Food Inspection Agency (CFIA) and the U.S. Food and Drug Administration (FDA) conducted a traceback investigation that implicated a single lot of frozen, precut coconut as the outbreak source. Grocery chain A voluntarily removed precut coconut pieces from their stores. This action likely limited the size and scope of this outbreak.


Subject(s)
Cocos/microbiology , Disease Outbreaks , Food Microbiology , Salmonella Food Poisoning/epidemiology , Salmonella/isolation & purification , Adolescent , Adult , Aged , Aged, 80 and over , Canada/epidemiology , Child , Child, Preschool , Electrophoresis, Gel, Pulsed-Field , Female , Humans , Infant , Male , Middle Aged , United States/epidemiology , Young Adult
9.
Int J Syst Evol Microbiol ; 68(1): 170-175, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29134937

ABSTRACT

Bogia coconut syndrome (BCS) is one of the lethal yellowing (LY)-type diseases associated with phytoplasma presence that are seriously threatening coconut cultivation worldwide. It has recently emerged, and is rapidly spreading in northern parts of the island of New Guinea. BCS-associated phytoplasmas collected in different regions were compared in terms of 16S rRNA gene sequences, revealing high identity among them represented by strain BCS-BoR. Comparative analysis of the 16S rRNA gene sequences revealed that BCS-BoR shared less than a 97.5 % similarity with other species of 'Candidatus Phytoplasma', with a maximum value of 96.08 % (with strain LY; GenBank accession no. U18747). This result indicates the necessity and propriety of a novel taxon for BCS phytoplasmas according to the recommendations of the IRPCM. Phylogenetic analysis was also conducted on 16S rRNA gene sequences, resulting in a monophyletic cluster composed of BCS-BoR and other LY-associated phytoplasmas. Other phytoplasmas on the island of New Guinea associated with banana wilt and arecanut yellow leaf diseases showed high similarities to BCS-BoR and were closely related to BCS phytoplasmas. Based on the uniqueness of their 16S rRNA gene sequences, a novel taxon 'Ca.Phytoplasma noviguineense' is proposed for these phytoplasmas found on the island of New Guinea, with strain BCS-BoR (GenBank accession no. LC228755) as the reference strain. The novel taxon is described in detail, including information on the symptoms of associated diseases and additional genetic features of the secY gene and rp operon.


Subject(s)
Cocos/microbiology , Musa/microbiology , Phylogeny , Phytoplasma/classification , Plant Diseases/microbiology , Bacterial Typing Techniques , Base Composition , DNA, Bacterial/genetics , Islands , New Guinea , Phytoplasma/genetics , Phytoplasma/isolation & purification , Polymorphism, Restriction Fragment Length , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
10.
Int J Syst Evol Microbiol ; 68(10): 3125-3131, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30132753

ABSTRACT

Phylogenetic analysis was performed on a cellulose-producing strain, designated WE7T, isolated from contaminated coconut milk. The analysis utilized nearly complete 16S rRNA gene sequences, as well as concatenated partial sequences of the housekeeping genes dnaK, groEL and rpoB, and allowed identification of the strain as belonging to the genus Komagataeibacter. DNA-DNA correlation or average nucleotide identity analysis was performed between WE7T and its closest phylogenetic neighbours, and the resulting values were below the species level (<70 % and <95 %), suggesting that the strain represents a novel species in genus Komagataeibacter. Strain WE7T was coupled with Komagataeibacter species more tightly than with Gluconacetobacter species in a 16S rRNA gene sequence phylogenetic tree. Strain WE7T can be differentiated from closely related Komagataeibacter and Gluconacetobacter entanii species by the ability to grow on the carbon sources d-mannitol, sodium d-gluconate and glycerol, the ability to form acid by d-fructose, sucrose, d-mannitol, d-galactose and ethanol, and the ability to grow without acetic acid. The major fatty acid of WE7T is C18 : 1ω9c (52.3 %). The DNA G+C content of WE7T is 63.2 mol%. The name Komagataeibacter cocois sp. nov. is proposed, with the type strain WE7T (=CGMCC 1.15338T=JCM 31140T).


Subject(s)
Acetobacteraceae/classification , Cocos/microbiology , Fermented Foods/microbiology , Food Microbiology , Phylogeny , Acetobacteraceae/genetics , Acetobacteraceae/isolation & purification , Animals , Bacterial Typing Techniques , Base Composition , China , DNA, Bacterial/genetics , Fatty Acids/chemistry , Genes, Bacterial , Nucleic Acid Hybridization , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
11.
J Sci Food Agric ; 98(2): 534-540, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28631270

ABSTRACT

BACKGROUND: Vinegar is widely used as a food additive, in food preparation and as a food supplement. This study compared the phenolic acid profiles and in vivo toxicities, and antioxidant and immunomodulatory effects of coconut, nipah and pineapple juice vinegars, which were respectively prepared via a two-step fermentation using Saccharomyces cerevisiae 7013 INRA and Acetobacter aceti vat Europeans. RESULTS: Pineapple juice vinegar, which had the highest total phenolic acid content, also exhibited the greatest in vitro antioxidant capacity compared to coconut juice and nipah juice vinegars. Following acute and sub-chronic in vivo toxicity evaluation, no toxicity and mortality were evident and there were no significant differences in the serum biochemical profiles between mice administered the vinegars versus the control group. In the sub-chronic toxicity evaluation, the highest liver antioxidant levels were found in mice fed with pineapple juice vinegar, followed by coconut juice and nipah juice vinegars. However, compared to the pineapple juice and nipah juice vinegars, the mice fed with coconut juice vinegar, exhibited a higher population of CD4+ and CD8+ T-lymphocytes in the spleen, which was associated with greater levels of serum interleukin-2 and interferon-γ cytokines. CONCLUSIONS: Overall, the data suggested that not all vinegar samples cause acute and sub-chronic toxicity in vivo. Moreover, the in vivo immunity and organ antioxidant levels were enhanced, to varying extents, by the phenolic acids present in the vinegars. The results obtained in this study provide appropriate guidelines for further in vivo bioactivity studies and pre-clinical assessments of vinegar consumption. © 2017 Society of Chemical Industry.


Subject(s)
Acetic Acid/analysis , Ananas/chemistry , Antioxidants/analysis , Arecaceae/chemistry , Cocos/chemistry , Fruit and Vegetable Juices/analysis , Immunologic Factors/analysis , Acetic Acid/metabolism , Acetic Acid/toxicity , Acetobacter/metabolism , Ananas/metabolism , Ananas/microbiology , Animals , Antioxidants/metabolism , Antioxidants/toxicity , Arecaceae/metabolism , Arecaceae/microbiology , Cocos/metabolism , Cocos/microbiology , Fermentation , Fruit and Vegetable Juices/microbiology , Fruit and Vegetable Juices/toxicity , Immunologic Factors/metabolism , Immunologic Factors/toxicity , Interferon-gamma/immunology , Interleukin-2/immunology , Male , Mice , Mice, Inbred BALB C , Saccharomyces cerevisiae/metabolism , T-Lymphocytes/cytology , T-Lymphocytes/immunology
12.
World J Microbiol Biotechnol ; 32(7): 108, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27263003

ABSTRACT

The coconut root wilt disease (RWD) and the arecanut yellow leaf disease (YLD) are two major phytoplasma associated diseases affecting palms in South India. Greatly debilitating the palm health, these diseases cause substantial yield reduction and economic loss to farmers. A rapid and robust diagnostic technique is crucial in efficient disease management. We established phytoplasma 16S rDNA targeted loop mediated isothermal amplification (LAMP) and real time LAMP based diagnostics for coconut RWD and arecanut YLD. The LAMP reaction was set at 65 °C and end point detection made using hydroxynaphthol blue (HNB) and agarose gel electrophoresis. Molecular typing of LAMP products were made with restriction enzyme HpyCH4 V. Conventional PCR with LAMP external primers and sequencing of amplicons was carried out. Real time LAMP was performed on the Genei II platform (Optigene Ltd., UK). An annealing curve analysis was programmed at the end of the incubation to check the fidelity of the amplicons. The phytoplasma positive samples produced typical ladder like bands on agarose gel, showed colour change from violet to blue with HNB and produced unique annealing peak at 85 ± 0.5 °C in the real time detection. Restriction digestion produced predicted size fragments. Sequencing and BLASTN analysis confirmed that the amplification corresponded to phytoplasma 16S rRNA gene. LAMP method devised here was found to be more robust compared to conventional nested PCR and hence has potential applications in detection of phytoplasma from symptomatic palm samples and in rapid screening of healthy seedlings.


Subject(s)
Areca/microbiology , Cocos/microbiology , Phytoplasma/isolation & purification , Plant Diseases/microbiology , Bacteriological Techniques/methods , DNA, Bacterial/genetics , Electrophoresis, Agar Gel , India , Nucleic Acid Amplification Techniques/methods , Phytoplasma/genetics , Plant Leaves/microbiology , Plant Roots/microbiology , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
13.
Mol Genet Genomics ; 290(5): 1899-910, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25893418

ABSTRACT

Invasive phytoplasmas wreak havoc on coconut palms worldwide, leading to high loss of income, food insecurity and extreme poverty of farmers in producing countries. Phytoplasmas as strictly biotrophic insect-transmitted bacterial pathogens instigate distinct changes in developmental processes and defence responses of the infected plants and manipulate plants to their own advantage; however, little is known about the cellular and molecular mechanisms underlying host-phytoplasma interactions. Further, phytoplasma-mediated transcriptional alterations in coconut palm genes have not yet been identified. This study evaluated the whole transcriptome profiles of naturally infected leaves of Cocos nucifera ecotype Malayan Red Dwarf in response to yellow decline phytoplasma from group 16SrXIV, using RNA-Seq technique. Transcriptomics-based analysis reported here identified genes involved in coconut innate immunity. The number of down-regulated genes in response to phytoplasma infection exceeded the number of genes up-regulated. Of the 39,873 differentially expressed unigenes, 21,860 unigenes were suppressed and 18,013 were induced following infection. Comparative analysis revealed that genes associated with defence signalling against biotic stimuli were significantly overexpressed in phytoplasma-infected leaves versus healthy coconut leaves. Genes involving cell rescue and defence, cellular transport, oxidative stress, hormone stimulus and metabolism, photosynthesis reduction, transcription and biosynthesis of secondary metabolites were differentially represented. Our transcriptome analysis unveiled a core set of genes associated with defence of coconut in response to phytoplasma attack, although several novel defence response candidate genes with unknown function have also been identified. This study constitutes valuable sequence resource for uncovering the resistance genes and/or susceptibility genes which can be used as genetic tools in disease resistance breeding.


Subject(s)
Cocos/genetics , Genes, Plant , Phytoplasma/pathogenicity , Plant Leaves/genetics , Sequence Analysis, RNA , Transcriptome , Cocos/immunology , Cocos/microbiology , Immunity, Innate
14.
Int J Syst Evol Microbiol ; 64(Pt 6): 1890-1899, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24585372

ABSTRACT

In this study, the taxonomic position and group classification of the phytoplasma associated with a lethal yellowing-type disease (LYD) of coconut (Cocos nucifera L.) in Mozambique were addressed. Pairwise similarity values based on alignment of nearly full-length 16S rRNA gene sequences (1530 bp) revealed that the Mozambique coconut phytoplasma (LYDM) shared 100% identity with a comparable sequence derived from a phytoplasma strain (LDN) responsible for Awka wilt disease of coconut in Nigeria, and shared 99.0-99.6% identity with 16S rRNA gene sequences from strains associated with Cape St Paul wilt (CSPW) disease of coconut in Ghana and Côte d'Ivoire. Similarity scores further determined that the 16S rRNA gene of the LYDM phytoplasma shared <97.5% sequence identity with all previously described members of 'Candidatus Phytoplasma'. The presence of unique regions in the 16S rRNA gene sequence distinguished the LYDM phytoplasma from all currently described members of 'Candidatus Phytoplasma', justifying its recognition as the reference strain of a novel taxon, 'Candidatus Phytoplasma palmicola'. Virtual RFLP profiles of the F2n/R2 portion (1251 bp) of the 16S rRNA gene and pattern similarity coefficients delineated coconut LYDM phytoplasma strains from Mozambique as novel members of established group 16SrXXII, subgroup A (16SrXXII-A). Similarity coefficients of 0.97 were obtained for comparisons between subgroup 16SrXXII-A strains and CSPW phytoplasmas from Ghana and Côte d'Ivoire. On this basis, the CSPW phytoplasma strains were designated members of a novel subgroup, 16SrXXII-B.


Subject(s)
Cocos/microbiology , Phylogeny , Phytoplasma/classification , Plant Diseases/microbiology , Bacterial Typing Techniques , DNA, Bacterial/genetics , Molecular Sequence Data , Mozambique , Phytoplasma/genetics , Phytoplasma/isolation & purification , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
15.
Biosci Biotechnol Biochem ; 78(3): 533-41, 2014.
Article in English | MEDLINE | ID: mdl-25036846

ABSTRACT

From the pellicle formed on top of brewing coconut water vinegar in Sri Lanka, three Acetobacter strains (SL13E-2, SL13E-3, and SL13E-4) that grow at 42 °C and four Gluconobacter strains (SL13-5, SL13-6, SL13-7, and SL13-8) grow at 37 °C were identified as Acetobacter pasteurianus and Gluconobacter frateurii, respectively. Acetic acid production by the isolated Acetobacter strains was examined. All three strains gave 4% acetic acid from 6% initial ethanol at 37 °C, and 2.5% acetic acid from 4% initial ethanol at 40 °C. Compared with the two other strains, SL13E-4 showed both slower growth and slower acetic acid production. As well as the thermotolerant SKU1108 strain, the activities of the alcohol dehydrogenase and the aldehyde dehydrogenase of SL13E-2 and SL13E-4 were more stable than those of the mesophilic strain. The isolated strains were used to produce coconut water vinegar at higher temperatures than typically used for vinegar production.


Subject(s)
Acetic Acid/metabolism , Cocos/microbiology , Fermentation , Gluconobacter/metabolism , Acetic Acid/chemistry , Alcohol Dehydrogenase/chemistry , Aldehyde Dehydrogenase/chemistry , Enzyme Stability , Ethanol/chemistry , Gluconobacter/enzymology , Gluconobacter/isolation & purification , Hot Temperature , RNA, Ribosomal, 16S/genetics , Sri Lanka
16.
Lett Appl Microbiol ; 59(2): 139-46, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24684306

ABSTRACT

UNLABELLED: This study evaluated the use of sodium benzoate (SB) and licorice root extract (LRE) as heat-sensitizing additives against Escherichia coli O157:H7 in mildly heated young coconut liquid endosperm. Consumer acceptance scoring showed that maximum permissible supplementation (MPS) levels for SB and LRE were at 300 and 250 ppm, respectively. The MPS values were considered in the generation of a 2-factor rotatable central composite design for the tested SB and LRE concentration combinations. Liquid endosperm with various SB and LRE supplementation combinations was inoculated with E. coli O157:H7 and heated to 55°C. The susceptibility of the cells towards heating was expressed in terms of the decimal reduction time (D55 ). Response surface analysis showed that only the individual linear effect of benzoate significantly influenced D55 value, where increasing supplementation level resulted in increasing susceptibility. The results reported could serve as baseline information in further investigating other additives that could be used as heat-sensitizing agents against pathogens in heat-labile food systems. SIGNIFICANCE AND IMPACT OF THE STUDY: Fruit juice products have been linked to outbreaks of microbial infection, where unpasteurized products were proven vectors of diseases. Processors often opt not to apply heat process to juice products as the preservation technique often compromises the sensorial quality. This work evaluated two common additives for their heat-sensitizing effects against E. coli O157:H7 in coconut liquid endosperm, the results of which may serve as baseline information to small- and medium-scale processors, and researchers in the establishment of mild heat process schedule for the test commodity and other similar products.


Subject(s)
Anti-Bacterial Agents/pharmacology , Beverages/microbiology , Cocos/chemistry , Endosperm/chemistry , Escherichia coli O157/drug effects , Glycyrrhiza/chemistry , Sodium Benzoate/pharmacology , Antioxidants/pharmacology , Cocos/microbiology , Endosperm/microbiology , Escherichia coli O157/physiology , Food Microbiology , Food Preservation/methods , Hot Temperature , Microbial Viability , Plant Extracts/pharmacology
17.
PeerJ ; 12: e17502, 2024.
Article in English | MEDLINE | ID: mdl-38952971

ABSTRACT

Background: Desserts with vegetable ingredients are a constantly expanding global market due to the search for alternatives to cow's milk. Fermentation of these matrices by lactic acid bacteria can add greater functionality to the product, improving its nutritional, sensory, and food safety characteristics, as well as creating bioactive components with beneficial effects on health. Concern for health and well-being has aroused interest in byproducts of the industry that have functional properties for the body, such as mature coconut water, a normally discarded residue that is rich in nutrients. This study aimed to develop a probiotic gelatin based on pulp and water from mature coconuts and evaluate the physicochemical characteristics, viability of the Lacticaseibacillus rhamnosus LR32 strain in the medium, as well as the texture properties of the product. Methods: After collection and cleaning, the physicochemical characterization, mineral analysis, analysis of the total phenolic content and antioxidant activity of mature coconut water were carried out, as well as the centesimal composition of its pulp. Afterwards, the gelling was developed with the addition of modified corn starch, gelatin, sucrose, and probiotic culture, being subjected to acidity analysis, texture profile and cell count, on the first day and every 7 days during 21 days of storage, under refrigeration at 5 °C. An analysis of the centesimal composition was also carried out. Results: The main minerals in coconut water were potassium (1,932.57 mg L-1), sodium (19.57 mg L-1), magnesium (85.13 mg L-1) calcium (279.93 mg L-1) and phosphorus (11.17 mg L- 1), while the pulp had potassium (35.96 g kg-1), sodium (0.97 g kg-1), magnesium (2.18 g kg-1), 37 calcium (1.64 g kg-1), and phosphorus (3.32 g kg-1). The phenolic content of the water and pulp was 5.72 and 9.77 mg gallic acid equivalent (GAE) 100 g-1, respectively, and the antioxidant capacity was 1.67 and 0.98 39 g of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) mg-1, respectively. The coconut pulp had 2.81 g 100 g-1of protein, 1.11 g 100 g-1 of 40 ash, 53% moisture, and 5.81 g 100 g-1 of carbohydrates. The gelatin produced during the storage period presented firmness parameters ranging from 145.82 to 206.81 grams-force (gf), adhesiveness from 692.85 to 1,028.63 gf sec, cohesiveness from 0.604 to 0.473, elasticity from 0.901 to 0.881, gumminess from 86.27 to 97.87 gf, and chewiness from 77.72 to 91.98 gf. Regarding the viability of the probiotic microorganism, the dessert had 7.49 log CFU g-1 that remained viable during the 21-day storage, reaching 8.51 CFU g-1. Acidity ranged from 0.15 to 0.64 g of lactic acid 100 g-1. The centesimal composition of the product showed 4.88 g 100 g-1 of protein, 0.54 g 100 g-1 of ash, 85.21% moisture, and 5.37g 100 g-1 of carbohydrates. The development of the gelatin made it possible to obtain a differentiated product, contributing to diversification in the food sector, providing a viable alternative for maintaining consumer health and reducing costs compared to desserts already available on the market.


Subject(s)
Cocos , Gelatin , Lacticaseibacillus rhamnosus , Probiotics , Cocos/chemistry , Cocos/microbiology , Gelatin/chemistry , Antioxidants/pharmacology , Antioxidants/chemistry , Fermentation
18.
Sci Rep ; 14(1): 11542, 2024 05 21.
Article in English | MEDLINE | ID: mdl-38773154

ABSTRACT

Evidence for seed transmission of phytoplasmas has grown in several pathosystems including coconut (Cocos nucifera). Bogia coconut syndrome (BCS) is a disease associated with the lethal yellowing syndrome associated with the presence of 'Candidatus Phytoplasma noviguineense' that affects coconut, betel nut (Areca catechu) and bananas (Musa spp.) in Papua New Guinea. Coconut and betel nut drupes were sampled from BCS-infected areas in Papua New Guinea, dissected, the extracted nucleic acid was used in polymerase chain reaction (PCR), and loop mediated isothermal amplification (LAMP) used to check for presence of phytoplasma DNA. In a second study, drupes of both plant species were collected from multiple field sites and grown in insect-proof cages. Leaf samples taken at 6 months were also tested with PCR and LAMP. The studies of dissected coconut drupes detected phytoplasma DNA in several tissues including the embryo. Drupes from betel nut tested negative. Among the seedlings, evidence of possible seed transmission was found in both plant species. The results demonstrate the presence of 'Ca. P. noviguineense' in coconut drupes and seedlings, and in seedlings of betel nut; factors that need to be considered in ongoing management and containment efforts.


Subject(s)
Areca , Cocos , Phytoplasma , Plant Diseases , Seedlings , Seeds , Cocos/microbiology , Phytoplasma/genetics , Phytoplasma/isolation & purification , Seeds/microbiology , Plant Diseases/microbiology , Seedlings/microbiology , Nucleic Acid Amplification Techniques/methods , DNA, Bacterial/genetics , Papua New Guinea , Polymerase Chain Reaction , Molecular Diagnostic Techniques
19.
J Food Prot ; 87(7): 100284, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38692353

ABSTRACT

Beverage innovation is a growing trend with a reliance on comanufacturing relationships to launch products quickly. A recent comanufacturing relationship is the utilization of dairy processing facilities to process plant-based beverages using high-temperature short-time (HTST) pasteurization. While the shelflife of HTST bovine milk is well established at 21 days, retailers are expecting new refrigerated beverages to achieve a 60-day shelflife. Little is known about the microbial stability of these new beverages, particularly those with complex formulations. Our objective was to identify bacterial taxa leading to the spoilage of four coconut-based creamers and their potential sources (raw ingredients or packaging). We used a multifaceted approach including plate counting and 16S rRNA metabarcoding to monitor microbial growth in products throughout shelflife (60 d, 4 °C), and cold enrichment (7 °C, 11 d) of ingredients and packaging. Nearly all product units (25/26) had elevated microbial loads (>4.3 log CFU/mL) prior to the 60-d target, with early spoilage detected at 21 d. Key spoilage taxa included Pseudomonas, Streptococcus, Aerococcus, Paenibacillus, Sphingomonas, and Oceanobacillus. Pseudomonas were responsible for "early" product spoilage (21-32 d), whereas Oceanobacillus were important in products with very "late" spoilage (60-62 d). All key spoilage taxa were identified in cold enrichments of multiple units of waxboard cartons. Paenibacillus was the dominant bacterium in 47% (10/21) of product units. In addition to carton samples, Paenibacillus was also identified in one raw ingredient (mushroom extract). Metabarcoding identified Listeria sensu stricto as a dominant taxon in three individual product units from three distinct production lots. Listeria was also found in 31% (5/16) of cold enrichments of individual cartons. Taxa responsible for spoilage of plant-based beverages were identified as well as demonstrating packaging as an important contamination source.


Subject(s)
Bacteria , Cocos , Food Contamination , Food Microbiology , Cocos/microbiology , Bacteria/classification , Food Contamination/analysis , Colony Count, Microbial , Animals , Beverages/microbiology , Cattle , Food Packaging/methods
20.
Food Microbiol ; 35(2): 73-85, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23664257

ABSTRACT

Two spontaneous Malaysian cocoa bean box fermentations (one farm, two plantation plots) were investigated. Physical parameters, microbial community dynamics, yeast and bacterial species diversity [mainly lactic acid bacteria (LAB) and acetic acid bacteria (AAB)], and metabolite kinetics were monitored, and chocolates were produced from the respective fermented dry cocoa beans. Similar microbial growth and metabolite profiles were obtained for the two fermentations. Low concentrations of citric acid were found in the fresh pulp, revealing low acidity of the raw material. The main end-products of the catabolism of the pulp substrates glucose, fructose, and citric acid by yeasts, LAB, and AAB were ethanol, lactic acid, acetic acid, and/or mannitol. Hanseniaspora opuntiae, Lactobacillus fermentum, and Acetobacter pasteurianus were the prevalent species of the two fermentations. Saccharomyces cerevisiae, Lactobacillus plantarum, Lactobacillus pentosus, and Acetobacter ghanensis were also found during the mid-phase of the fermentation processes. Leuconostoc pseudomesenteroides and Acetobacter senegalensis were among the prevailing species during the initial phase of the fermentations. Tatumella saanichensis and Enterobacter sp. were present in the beginning of the fermentations and they could be responsible for the degradation of citric acid and/or the production of gluconic acid and lactic acid, respectively. The presence of facultative heterofermentative LAB during the fermentations caused a high production of lactic acid. Finally, as these fermentations were carried out with high-quality raw material and were characterised by a restricted microbial species diversity, resulting in successfully fermented dry cocoa beans and good chocolates produced thereof, it is likely that the prevailing species H. opuntiae, S. cerevisiae, Lb. fermentum, and A. pasteurianus were responsible for it.


Subject(s)
Acetobacter/metabolism , Cocos/microbiology , Hanseniaspora/metabolism , Limosilactobacillus fermentum/metabolism , Saccharomyces cerevisiae/metabolism , Acetobacter/growth & development , Biodiversity , Cocos/metabolism , Fabaceae/metabolism , Fabaceae/microbiology , Fermentation , Food Microbiology , Hanseniaspora/growth & development , Limosilactobacillus fermentum/growth & development , Saccharomyces cerevisiae/growth & development
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