Complete Genome Sequence Data of Pseudomonas bijieensis SP1 Associated with Root Soft Rot of Yam Bean.

Pseudomonas bijieensis is a newly established species with antifungal activity. Here, we report the high-quality and complete genome sequence for P. bijieensis strain SP1, created by hybrid assembly using both short reads and long reads. The length of the circular chromosome is about 6.67 Mb, with a GC content of 60.89%. Bioinformatic analyses revealed gene clusters for the biosynthesis of antimicrobial metabolites 2,4-diacetylphloroglucinol as well as bacterial secretion systems (type I to III and type V to VI). Interestingly, this strain can cause soft rot symptoms in the roots of yam bean, showing the potential to be a plant pathogen. The genomic data will be a valuable resource for exploring the virulence mechanism and antifungal activity of this strain.

First report of bean common mosaic virus naturally infecting yam bean (Pachyrhizus erosus) in China.

Yam bean (Pachyrhizus erosus), a high-yielding leguminous root crop with good nutritional value, is widely cultivated in southern China. In 2020, P. erosus (cv. Mumashan) plants exhibiting irregular yellow leaves and malformed seed pods (Supplementary Fig S1) were observed at Ningbo city, Zhejiang Province, China. To determine the causal agent(s) of the disease, symptomatic leaves (n=4) were collected for electron microscopy negative staining. Virus particles with a length of about 700nm, similar to viruses in the genus Potyvirus, were observed via transmission electron microscope (TEM), suggesting the presence a potyvirus(es). To further confirm which potyvirus(es) infected yam bean, total RNA was extracted from leaf samples of a total of six plants, including four symptomatic plants and two asymptomatic plants using TRIzol reagent (Invitrogen Carlsbad, CA, USA) according to the manufacturer's instructions. RNA was reverse-transcribed into cDNA with M4-T as the 3'-anchoring primer by ReverTra Ace® kit (Toyobo, Japan). Sprimer/M4 Potyviridae specific primers (Chen et al., 2001) were used for PCR analysis. A ~1,700-bp-long product was amplified from four symptomatic plants using KOD FX enzyme (Toyobo, Japan). No such band was amplified from the two asymptomatic plants. The PCR product (~1.7kb) amplified from a single symptomatic plant was ligated into the pEASY®-Blunt Zero vector (TransGen Bio, Beijing, China) and sequenced (Sangon Bio, Shanghai, China). The amplicon showed 99% nucleotide sequence identities with bean common mosaic virus (BCMV) isolate NKY021 (KJ807819). Subsequently, the complete nucleotide sequences of this BCMV isolate (referred as BCMV-NB) was amplified by overlapping RT-PCR and rapid amplification of cDNA ends with primers (Supplementary Table S1) designed from the sequence of BCMV isolate NKY021. The BCMV-NB full genome (Accession No. OL871237) consists of 10,053 nucleotides excluding the poly(A) tail and contains a large open reading frame encoding a polyprotein of 3222 amino acids. BLASTn analysis showed that BCMV-NB shared a sequence identity of 96.4% with BCMV isolate HZZB011 (KJ807815). Phylogenetic tree generated by Neighbour-Joining method revealing the BCMV-NB isolate was grouped together with Chinese isolates from Glycine max (Supplementary Fig S1). To test the infectivity of BCMV-NB, virus-free yam bean (cv. Mumashan) and Nicotiana benthamiana seedlings were mechanically inoculated with sap extracted from the symptomatic leaves of a BCMV-NB-infected yam bean plant. The inoculated yam bean plants developed typical BCMV mosaic and chlorotic symptoms at 16 days post inoculation (dpi), while Nicotiana benthamiana had no obvious symptoms at 10 or 20 dpi (Supplementary Fig S1). BCMV infections were confirmed in yam bean plants (infection rate 6/6) and N. benthamiana plants (infection rate 8/8) by RT-PCR at 16 dpi and 10 dpi, respectively. Twelve further P. erosus plants (cv. Mumashan) were collected from a field in Ningbo city and tested by RT-PCR with BCMV-specific primer pair BCMV CP (+)/(-) (Supplementary Table 1). Eight out of the 12 samples tested positive for BCMV by PCR-gel electrophoresis (Supplementary Fig S1) and Sanger sequencing, suggesting a high incidence of BCMV infection in this field. BCMV infection in yam bean has been reported from Indonesia (Damayanti et al., 2008) and Peru (Fuentes et al., 2012). To the best of our knowledge, this is the first report of BCMV naturally infecting yam bean in China. Thus, special attention and appropriate management strategies are needed to minimize the damage caused by BCMV to yam bean crops in China.

Gastroprotective activities of Peperomia pellucida L. and Pachyrhizus erosus L. extracts combination on ethanol-induced rats.

Gastroprotective is an effect caused by the compounds that have the capability of protecting the gastric mucosa. Peperomia pellucida L. plants contain alkaloids, flavonoids, saponins, tannins, and terpenoids, while Pachyrhizus erosus L. contains flavonoids, alkaloids, tannins, and saponins. Peperomia pellucida L. reportedly contains dillapiole compounds with a gastroprotective effect. Moreover, its isolation result from Pachyrhizus erosus L. indicates the presence of dulcitol, gentisic acid, and formononetin, which has antioxidant activity. This study aims to determine the gastroprotective effect of the combination of Peperomia pellucida L. and Pachyrhizus erosus L. extract on rats with gastric ulcer models by looking at the ulcer index, percentage of inhibition, and histopathology. The research method used in this study was by making a combination of Peperomia pellucida L. and Pachyrhizus erosus L. extract. The combined extract was then given to five treatment groups. Group I as a negative control, group II as a positive control was given sucralfate, groups III, IV, and V were given a combination of Peperomia pellucida L. and Pachyrhizus erosus L. extract of 100, 200, and 400 mg/kg BW. The treatment was given orally for 14 days, after 1 h of treatment on the 14th day, 96% ethanol induction was given orally at a dose of 5 mg/kg BW. The animal dissection was performed 24 h after the induction. The results from observations showed an increase in body weight before and after the treatment. The ulcer index produced by negative control, positive control in the treatment with doses of 100, 200, and 400 were 4.18; 2.98; 2.42; 2.04; and 1.07. This study showed that the combination of Peperomia pellucida L. and Pachyrhizus erosus L. extract has a gastroprotective effect.

Chemical Constituents from the Leaves of Pachyrhizus erosus Collected in Vietnam.

A phytochemical investigation of methanol extract from leaves of Pachyrhizus erosus (L.) Urban, a leguminous shrub distributed in Vietnam and other tropical and subtropical countries led to the isolation of a new prenylated chalcone, erosusone (1) and a new megastigmane glycoside epimer, 3-episedumoside F1 (9), together with thirteen known compounds including flavonoids (2-6), a 3-benzoxepine lactone (7), a pyridine-4,5-diol derivative (8), megastigmanes and megastigmane glycosides (10-15). Their structures were elucidated by means of high resolution-electrospray ionization (HR-ESI)-MS, one dimensional (1D) and two-dimensional NMR (2D-NMR) spectroscopy as well as comparison with the data reported in the literature. The cytotoxic effects on LU-1 (lung carcinoma), HepG2 (hepatocellular carcinoma), and MCF7 (breast carcinoma) cell lines were assessed. Prenylated chalcones 1-2 and isoflavone 3 exhibited cytotoxicity against all tested cell lines with IC50 values ranging from 22.04 to 45.03 µM.

Evaluation of photosynthetic efficiency of yam bean (Pachyrhizus erosus L.) at saturating photon flux density under elevated carbon dioxide.

The future CO2 concentration is projected to reach 900-1000 ppm levels by the end of twenty-first century, pertaining to global climatic changes. Consequences of climate change such as changes in mean climatic conditions, increasing extreme weather events, relentless increase in atmospheric CO2 concentration and increasing pest damage pose serious threats to agricultural productivity. An experiment was planned to assess the response of yam bean to elevated CO2, as it is of paramount importance to identify photosynthetically efficient climate-smart crops and varieties to meet future food demand. The net photosynthetic rate (P n ), stomatal conductance (g s ) and intercellular CO2 (C i ) of yam bean variety, Rajendra Misrikand-1 was recorded under elevated carbon dioxide (400-1000 ppm) and photon flux density (PPFD; 50-2000 µmol m-2 h-1) at 30 ± 2 °C, 70-80% relative humidity and 0.8-1.2 kPa vapour pressure deficit. The mean P n rate steadily increased at 200-1000 ppm owing to enhanced intercellular CO2. The same trend was observed in the case of intercellular CO2. However, contrasting results were recorded with regard to g s , which steadily decreased at ascending carbon dioxide concentrations. Further, P n had a significant (P < 0.001) linear correlation with the PPFD (R2 = 0.973). Yam bean was found to be responsive to elevated carbon dioxide as P n rate at 1000 ppm increased up to 23% relative to 400 ppm.

Oviposition deterrent activities of Pachyrhizus erosus seed extract and other natural products on Plutella xylostella (Lepidoptera: Plutellidae).

An extract of a rotenone-containing plant yam bean, Pachyrhizus erosus (L.) Urban, seeds was tested against the diamondback moth, Plutella xylostella (L.) in a greenhouse to determine its potential as an oviposition deterrent and compared with coumarin and rutin, known as diamondback moth oviposition deterrent compounds, rotenone, and an extract of Peruvian cube root, at a concentration of 0.5% (w/v). Oviposition deterrent index (ODI) was used to determine effects of extracts or compounds in inhibiting oviposition of diamondback moth. Coumarin showed a stronger deterrent effect than the yam bean seed extract with a higher ODI value. On the contrary, rotenone, rutin, and the cube root extract, containing 6.7% (w/w) of rotenone, showed no significant deterrent effects having low or negative ODI values, suggesting that the deterrent effect of the yam bean seed extract is not due to rotenone content of the yam bean seeds. The extract of yam bean seed and coumarin partially deterred the moth from laying eggs on treated leaves in a concentration-dependent manner. The effective concentration for 50% deterrency of coumarin and the yam bean seed extract were 0.11 and 0.83% (w/v), respectively. However, the yam bean seed extract showed a residual deterrent effect on the moth even at 3 d after the treatment and is probably because of its low volatile nature. A long-term deterrency of the yam bean seed extract is an advantage over coumarins. Both the yam bean seed extract and coumarin deterred diamondback moth from laying eggs in total darkness, indicating their nonvisual deterrent effect. This made the extract an effective deterrence to diamondback moth in light and in darkness. To conclude, this study revealed the potential of the crude extract of the yam bean seed to prevent diamondback moth from ovipositing on its plant host.

The effect of jicama (Pachyrhizus erosus L.) starch on the properties and probiotic potential of L. plantarum SN13T fermented milk.

Objective: This study investigated the application of Jicama starch (Pachyrhizus erosus L.) as a stabilizing agent to enhance the longevity and integrity of fermented milk. Materials and Methods: Lactobacillus plantarum SN13T (6 gm/100 ml) and Jicama starch (2 gm/100 ml) were added into pasteurized milk (65°C, 30 min) and then incubated under anaerobic conditions at 37°C for 18 h. The fermented milk was stored at 4°C. The evaluation on proximate composition, pH, titratable acidity (TA), viscosity, water holding capacity (WHC), syneresis, total lactic acid bacteria (LAB), and hedonic sensory evaluation was conducted at 1, 7, 14, 21, and 28 days of storage. Results: Throughout the storage period, fermented milk enriched with Jicama starch significantly (p < 0.05) increased pH, TA, population dynamics of LAB, viscosity, WHC, and syneresis. It effectively sustained WHC and mitigated syneresis, thus ensuring the preservation of vital product quality. Furthermore, the quantity of LAB within the fermented milk consistently met the probiotic threshold of 84.50 × 108 CFU/ml. The hedonic sensory evaluation results indicated that fermented milk showed consistent sensory attributes throughout storage, except for overall acceptance, which declined on day 28. Conclusion: The addition of Jicama starch revealed a promising health probiotic product, presenting a viable avenue for delivering probiotic benefits to consumers while maintaining the palatability and efficacy of the product.

Characterizing Nanoparticle Isolated by Yam Bean (Pachyrhizus erosus) as a Potential Agent for Nanocosmetics: An in vitro and in vivo Approaches.

BACKGROUND: This study investigated the potential of Plant-Derived Exosome-Like Nanoparticles (PDENs) as cosmeceutical nanocarriers for treating skin problems, such as scar removal, face rejuvenation, anti-aging, and anti-pigmentation. OBJECTIVE: Researchers isolated PDENs from Yam Bean (Pachyrhizus erosus) using PEG-based precipitation, gradual filtration, and various centrifugations at low temperatures. Followed by in vitro and in vivo studies using HDF cells and Zebrafish. METHODS: The morphology of the YB-PDENs was determined using TEM analysis, they had a spherical shape with diameters of 236,83 ± 9,27nm according to PSA. The study found that YB-PDENs were stable in aquabidest at 4°C for one month of storage and had ~-26,5 mV of Zeta Potential. The concentration of YB-PDENs was measured using the BCA Assay, and internalization of YB-PDENs to HDF cells was observed using a Confocal Laser Scanning Microscope labelled with PKH67. RESULT: As for cytotoxicity, after 24 and 72 hours of incubation with YB-PDENs, the viability of HDF cells remained more than 80%. The study also examined cell migration using the Scratch Assay and found that at 2,5 µg/mL, YB-PDENs had better migration results than other concentrations. Immunocytochemistry showed that collagen expression was higher after 14 days of incubation with YB-PDENs, and melanocytes in zebrafish decreased at each concentration compared with controls. CONCLUSION: In conclusion, this study is the first to extract and describe PDENs from Yam Bean (Pachyrhizus erosus), with YB-PDENs having a promising anti-melanogenic effect in skin treatment. This study highlights the potential of YB-PDENs as a promising alternative to depigmentation and skin whitening treatments.

Bacterial cellulose production from Komagataeibacter xylinus TISTR 1011 and Komagataeibacter nataicola TISTR 975 using yam bean juice as a nutrient source.

The present study investigated the efficacy of bacterial cellulose production by K. xylinus TISTR 1011 and K. nataicola TISTR 975 using yam bean juice as a nutrient source, and the physicochemical and sensory characteristics of bacterial cellulose were examined. Bacterial cellulose content, production yield, and production rate were significantly higher when K. xylinus TISTR 1011 rather than K. nataicola TISTR 975 was used as the bacterial strain. The analysis of physicochemical characteristics revealed that bacterial cellulose produced by K. xylinus TISTR 1011 using yam bean juice medium had higher scores for CIE L*, a*, and b* values, wet weight, moisture content, firmness, and gel strength than bacterial cellulose produced by K. nataicola TISTR 975. In contrast, sensory evaluation showed that the acceptability scores and preference of all attributes of bacterial cellulose produced by K. nataicola TISTR 975 using yam bean juice medium were higher than those of bacterial cellulose produced by K. xylinus TISTR 1011. The results of this study indicate that yam bean juice from yam bean tubers, an alternative raw material agricultural product, can be used as a nutrient source for producing bacterial cellulose or nata by Komagataeibacter strains.

Treating the Onset of Diabetes Using Probiotics Along with Prebiotic from Pachyrhizus erosus in High-Fat Diet Fed Drosophila melanogaster.

The increasing mortality due to hypertension and hypercholesterolemia is directly linked with type-2 diabetes. This shows the lethality of the disease. Reports suggest that the prebiotics along with probiotics help in lowering the effects of type-2 diabetes. Prebiotic like inulin is best known for its anti-diabetic effect. The current study utilizes jicama extract as prebiotic source of inulin along with the bacterial strains with probiotic properties (Lactiplantibacillus plantarum and Enterococcus faecium) for treating type-2 diabetes in high-fat diet-induced Drosophila melanogaster model. The high-fat diet-induced Drosophila showed deposition of lipid droplets and formation of micronuclei in the gut. The larva and adult treated with probiotics and synbiotic (probiotic + prebiotic- inulin) comparatively reduced the lipid deposition and micronuclei number in the gut. The increased amount of triglyceride in the whole body of the fatty larva and adult indicated the onset of diabetes. The overexpression of insulin-like genes (Dilp 2) and (Dilp 5) confirmed the insulin resistance, whereas the expression was reduced in the larva and adult supplemented with probiotics and synbiotic. The reactive oxygen species level was reduced with the supplementation of probiotics. The weight, larva size, crawling speed and climbing were also altered in high-fat diet-induced Drosophila melanogaster. The study confirmed the effects of probiotics and synbiotic in successfully lowering diabetes in Drosophila. The study also proved the anti-diabetic potential of the probiotics. Further, it was also confirmed that the probiotics work better in the presence of prebiotic.

Inulin from Pachyrhizus erosus root and its production intensification using evolutionary algorithm approach and response surface methodology.

Production of inulin from yam bean tubers by ultrasonic assisted extraction (UAE) was optimized by using response surface methodology (RSM) and genetic algorithms (GA). Yield of inulin was obtained between 11.97%-12.15% for UAE and 11.21%-11.38% for microwave assisted extraction (MAE) using both the methodologies, significantly higher than conventional method (9.9 %) using optimized conditions. Under such optimized condition, SEM image of root tissues before and extraction showed disruption and microfractures over surface. UAE provided a shade better purity of extracted inulin than other two techniques. Degree of polymerization in inulin was also recorded to be better, might be due lesser degradation during extraction. Significant prebiotic activity was recorded while evaluation using Lactobacillus fermentum and it was 36 % more than glucose treatment. Energy density by UAE was few fold lesser than MAE. Carbon emission was far more less in both these methods than the conventional one.

The Bioactivity and Phytochemicals of Pachyrhizus erosus (L.) Urb.: A Multifunctional Underutilized Crop Plant.

Pachyrhizus erosus (L.) Urb. is an underutilized crop plant belonging to the Fabaceae family. In recent years, the plant received huge attention and was introduced in different countries owing to properties such as a high nutritional content, its nitrogen-fixing abilities, and different biological activities such as its antioxidant, immune modulation, anticancer, anti-diabetes, anti-osteoporosis, antiviral, and antiaging affects, among others. In this review, an attempt has been made to comprehensively compile the biological activities of the plant to provide a panoramic view of the current efforts and further directions, which may lead to the development of pharmacological applications. This information will be helpful in creating interest towards P. erosus and it may be useful in developing the plant for medical applications and/or as a functional food. More than 50 phytochemicals have been reported from the plant, which belong to different chemical classes such as triterpenoids, organic acid, flavonoids, and fatty acids. Numerous biological activities were reported from the plant through in vivo, in vitro, ex vivo, and human studies. However, well-defined clinical studies are still lacking for the establishment of any biological properties that could be further developed. Suggestions for the further development of P. erosus, according to current knowledge about the different biological properties, has also been provided.

Determination of the chemical and functional properties of yam bean (Pachyrhizus erosus (L.) Urban) flour for food systems.

Many plant species that are suitable for food across the world are neglected and underutilized. In order to increase their diversified food uses and thus help enhance food and nutrition security, we studied the chemical and functional properties of Pachyrhizus erosus (yam bean), which is a neglected and underutilized legume species. The chemical properties of flour produced from the yam bean include 5.8% moisture content, 5.7% crude fat, 6.2% crude fiber, and 85% available carbohydrate, indicating appropriate shelf-stable flour, low fat, and abundant energy. The results also showed a reducing sugar content of 2.0% and 21.0% starch. Pasting temperature was 70.6°C with peak viscosity of 14.5 BU, which supports ease of cooking of the flour. The swelling power obtained was 752.9 g/100 g at 85°C with a solubility index of 54%. Water holding capacity (WHC) obtained for the flour was 363.88%, whereas swelling volume was 14.0 ml and makes the flour appropriate for the production of infant foods. The P. erosus flour therefore exhibits good functional and chemical properties that would make the flour quite suitable as a substitute for other flours in food systems.

Ecotypic differentiation under farmers' selection: Molecular insights into the domestication of Pachyrhizus Rich. ex DC. (Fabaceae) in the Peruvian Andes.

Understanding the distribution of crop genetic diversity in relation to environmental factors can give insights into the eco-evolutionary processes involved in plant domestication. Yam beans (Pachyrhizus Rich. ex DC.) are leguminous crops native to South and Central America that are grown for their tuberous roots but are seed-propagated. Using a landscape genetic approach, we examined correlations between environmental factors and phylogeographic patterns of genetic diversity in Pachyrhizus landrace populations. Molecular analyses based on chloroplast DNA sequencing and a new set of nuclear microsatellite markers revealed two distinct lineages, with strong genetic differentiation between Andean landraces (lineage A) and Amazonian landraces (lineage B). The comparison of different evolutionary scenarios for the diversification history of yam beans in the Andes using approximate Bayesian computation suggests that Pachyrhizus ahipa and Pachyrhizus tuberosus share a progenitor-derivative relationship, with environmental factors playing an important role in driving selection for divergent ecotypes. The new molecular data call for a revision of the taxonomy of Pachyrhizus but are congruent with paleoclimatic and archeological evidence, and suggest that selection for determinate growth was part of ecophysiological adaptations associated with the diversification of the P. tuberosus-P. ahipa complex during the Mid-Holocene.

Starch extraction process coupled to protein recovery from leguminous tuberous roots (Pachyrhizus ahipa).

The objective of this work was to fit together the starch extraction from Pachyrhizus ahipa roots and the recovery of the proteins present in these storage organs, making an improved use of this novel raw material. The replacement of water by buffer PO4(-3)/NaCl as solvent in the first extraction steps improved protein extraction without lowering the starch yield. The starches obtained from the traditional and the proposed methods exhibited some differences in appearance and technological and thermal properties, which were endorsed to the adjustment in the methodology of extraction rather than to the use of buffer as solvent. Thus, P. ahipa starch obtaining procedure could be coupled to protein extraction with a minimum change in the methodology. This innovation did not significantly shift the characteristics of the starch obtained and allowed to obtain a protein yield of 135.7mg BSA equivalent protein/100g of fresh roots.

Rotenone isolated from Pachyrhizus erosus displays cytotoxicity and genotoxicity in K562 cells.

Pachyrhizus erosus (Fabaceae) is a herb commonly known as 'yam bean', which has been cultivated in México since pre-Columbian times for its edible tubers. The seeds are also known for their acaricidal and insecticidal properties due to rotenone and other isoflavonoid contents. Rotenone has exhibited cytotoxic activity against several human tumour cell lines; however, its mechanism of action is still not fully understood. In this study, we determined the cytotoxicity of rotenone isolated from P. erosus seeds on K562 human leukaemia cells. Rotenone exhibited significant cytotoxic activity (IC50 = 13.05 µM), as determined by the MTT assay. Three other isolated isoflavonoids were not cytotoxic. Rotenone genotoxicity was detected using the comet assay. Rotenone induced cell death, and caspase-3 activation as indicated by TUNEL assay, and immunocytofluorescence. Plasmid nicking assay indicated that rotenone does not interact directly with DNA.

Microsatellite markers for the yam bean Pachyrhizus (Fabaceae).

PREMISE OF THE STUDY: Microsatellite loci were developed for the understudied root crop yam bean (Pachyrhizus spp.) to investigate intraspecific diversity and interspecific relationships within the genus Pachyrhizus. • METHODS AND RESULTS: Seventeen nuclear simple sequence repeat (SSR) markers with perfect di- and trinucleotide repeats were developed from 454 pyrosequencing of SSR-enriched genomic libraries. Loci were characterized in P. ahipa and wild and cultivated populations of four closely related species. All loci successfully cross-amplified and showed high levels of polymorphism, with number of alleles ranging from three to 12 and expected heterozygosity ranging from 0.095 to 0.831 across the genus. • CONCLUSIONS: By enabling rapid assessment of genetic diversity in three native neotropical crops, P. ahipa, P. erosus, and P. tuberosus, and two wild relatives, P. ferrugineus and P. panamensis, these markers will allow exploration of the genetic diversity and evolutionary history of the genus Pachyrhizus.

Volatile organic compounds from pachyrhizus ferrugineus and pachyrhizus erosus (Fabaceae) leaves / Compuestos orgánicos volátiles de las hojas de pachyrhizus ferrugineus y pachyrhizus erosus (Fabaceae)

In México, Pachyrhizus erosus (Fabaceae) commonly called "jícama", is widely known for its edible tubers. It is cultivated since the pre-Columbian period, and the powdered seeds have been used for the treatment of mange, lice, and fleas, due to their content of rotenone, a well-known insecticidal compound. On the other hand, P. ferrugineus, a wild species can only be found in the Tropical Forests, and has no commercial value. It is known that plants release volatile organic compounds (VOCs) showing qualitative and quantitative differences if are wild or cultivated. VOCs are also involved as repelling or attracting chemical signals to insect herbivores, and their natural enemies. Until now, the VOCs of the leaves of P. erosus and P. ferrugineus have not been investigated. In the present contribution the VOCs of both species were characterized by headspace solid-phase (HS-SPME) extraction and gas chromatography-mass spectrometry (GC-MS-TOF). In P. erosus 21 VOCs were found, being the most abundant: cyclohexanone (32.8 percent), 3-hexen-1-ol (Z) (32.7 percent), 3-hexenal (Z) (10.5 percent). The majoritarian compounds were C6 or C5 derivatives In P. ferrugineus, the most abundant VOCs were: 5-hexene-1-ol acetate (51.5 percent), undecanal (22.4 percent), 2-hepten-1-al (14.5 percent). The majoritarian compounds were C6, C7 or C11 derivatives.

En México, Pachyrhizus erosus (Fabaceae) es llamada comúnmente "jícama" y es conocida por sus tubérculos comestibles. Se ha cultivado desde el período pre-Colombino y las semillas se han utilizado para el tratamiento tópico de la sarna, piojos, pulgas; las semillas contienen rotenona, un compuesto insecticida. Por otra parte, P. ferrugineus solo está presente en estado silvestre en los bosques tropicales y carece de valor comercial. Se sabe que las plantas liberan compuestos orgánicos volátiles (COV) y muestran diferencias cualitativas y cuantitativas dependiendo, si son silvestres o cultivadas. Los COV también son señales químicas atrayentes o repelentes de los insectos herbívoros y a sus enemigos naturales. Hasta ahora, los COV en las hojas de P. erosus y P. ferrugineus no han sido investigados. En el presente trabajo, los COV se identificaron mediante la microextracción (HS-SPME) en fase sólida, e identificados por cromatografía de gases acoplada a espectrometría de masas (GC-MS-TOF). En P. erosus se encontraron 21 COV, siendo los más abundantes: ciclohexanona (32.8 por ciento), 3-hexen-1-ol (Z) (32.7 por ciento) y 3-hexenal (Z) (10.5 por ciento). Los compuestos mayoritarios son C6 y C5. En P. ferrugineus los más abundantes fueron: 5-hexen-1-ol acetato (51.5 por ciento), undecanal (22.4 por ciento) y 2-hepten-1-al (14.5 por ciento). Los compuestos mayoritarios son C6, C7 o C11.

Interspecies variation of Kitasatospora recifensis endophytic from yam bean producing thermostable amylases in alternative media.

An endophytic actinomycete isolated from tubers of yam beam (Pachyrhizus erosus L. Urban) was classified as a novel species nominated Kitasatospora recifensis based in phenotypic and genotypic analysis (16S rDNA gene sequence). Monosporic culture using specific ISP2 media revealed three interspecies, which were identified by DNA southern hybridization (Wild strain 13817 W, Aerial Mycelium strain 13817 AM and Vegetative Mycelium strain 13817 VM). The strains were tested for the production of amylolitic enzymes in alternative media. Maximum yields for both enzymes were observed in starch-casein. Higher α-amylase was obtained with strain 13817 W in starch-urea, and amyloglucosidase with strain 13817 AM in starch-ammonium that are economic sources and may be important for industrial purposes. Type strain (DAUFPE 13817(T) = KCTC 9972(T )= DSM 44943(T)).