Xylanopectinolytic enzymes by marine actinomycetes from sediments of Sarena Kecil, North Sulawesi: high potential to produce galacturonic acid and xylooligosaccharides from raw biomass.

BACKGROUND: Actinomycetes isolated from marine habitats are known to have the potential for novel enzymes that are beneficial in the industry. In-depth knowledge is necessary given the variety of this bacterial group in Indonesia and the lack of published research. Actinomycetes isolates (BLH 5-14) obtained from marine sediments of Sarena Kecil, Bitung, North Sulawesi, Indonesia, showed an ability to produce pectinase and xylanase that have equal or even higher potential for pectic-oligosaccharides (POS) and xylooligosaccharides (XOS) production from raw biomass than from commercial substrates. This study's objective was to characterize both enzymes to learn more for future research and development. RESULTS: Pectinase had the highest activity on the 6th day (1.44±0.08 U/mL) at the optimum pH of 8.0 and optimum temperature of 50 °C. Xylanase had the maximum activity on the 6th day (4.33±0.03 U/mL) at optimum pH 6.0 and optimum temperature 60 °C. Hydrolysis and thin layer chromatography also showed that pectinase was able to produce monosaccharides such as galacturonic acid (P1), and xylanase was able to yield oligosaccharides such as xylotriose (X3), xylotetraose (X4), and xylopentaose (X5). BLH 5-14 identified as the genus Streptomyces based on the 16S rDNA sequences and the closely related species Streptomyces tendae (99,78%). CONCLUSIONS: In the eco-friendly paper bleaching industry, Streptomyces tendae has demonstrated the potential to create enzymes with properties that can be active in a wide range of pH levels. The oligosaccharides have the potential as prebiotics or dietary supplements with anti-cancer properties. Further research is needed to optimize the production, purification, and development of the application of pectinase and xylanase enzymes produced by Actinomycetes isolates.

Mining Indonesian Microbial Biodiversity for Novel Natural Compounds by a Combined Genome Mining and Molecular Networking Approach.

Indonesia is one of the most biodiverse countries in the world and a promising resource for novel natural compound producers. Actinomycetes produce about two thirds of all clinically used antibiotics. Thus, exploiting Indonesia's microbial diversity for actinomycetes may lead to the discovery of novel antibiotics. A total of 422 actinomycete strains were isolated from three different unique areas in Indonesia and tested for their antimicrobial activity. Nine potent bioactive strains were prioritized for further drug screening approaches. The nine strains were cultivated in different solid and liquid media, and a combination of genome mining analysis and mass spectrometry (MS)-based molecular networking was employed to identify potential novel compounds. By correlating secondary metabolite gene cluster data with MS-based molecular networking results, we identified several gene cluster-encoded biosynthetic products from the nine strains, including naphthyridinomycin, amicetin, echinomycin, tirandamycin, antimycin, and desferrioxamine B. Moreover, 16 putative ion clusters and numerous gene clusters were detected that could not be associated with any known compound, indicating that the strains can produce novel secondary metabolites. Our results demonstrate that sampling of actinomycetes from unique and biodiversity-rich habitats, such as Indonesia, along with a combination of gene cluster networking and molecular networking approaches, accelerates natural product identification.

Complete Genome Sequence of the Putative Phosphonate Producer Streptomyces sp. Strain I6, Isolated from Indonesian Mangrove Sediment.

Streptomyces sp. strain I6 is a novel strain isolated from an Indonesian mangrove sediment sample. Bioinformatic analysis of the genome sequence of Streptomyces sp. I6 revealed 23 biosynthetic gene clusters. One of them encodes the synthesis of a putative phosphonate secondary metabolite, a class of underexplored natural compounds with great pharmaceutical potential.

Complete Genome Sequence of Streptomyces sp. Strain SHP22-7, a New Species Isolated from Mangrove of Enggano Island, Indonesia.

Streptomyces sp. SHP22-7 is a novel strain isolated from a mangrove sample on Enggano Island, Indonesia. Here, we present the 7.9-Mbp genome sequence of SHP22-7, which will provide insight into its natural compound biosynthetic potential.

Complete Genome Sequence of Streptomyces sp. Strain BSE7F, a Bali Mangrove Sediment Actinobacterium with Antimicrobial Activities.

The strain Streptomyces sp. BSE7F, a novel Streptomyces strain isolated from Indonesian mangrove sediment, displays antimicrobial activities against Gram-positive bacteria, Gram-negative bacteria, and yeast. Bioinformatic analysis of the genome sequence revealed the occurrence of 22 biosynthetic gene clusters disclosing the secondary metabolite capacity of strain BSE7F.

Kocuria pelophila sp. nov., an actinobacterium isolated from the rhizosphere of a mangrove.

A novel spherical actinobacterium, designated RS-2-3T, was isolated from the rhizosphere of a mangrove growing on Rambut Island, Indonesia, and its taxonomic position was investigated using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that strain RS-2-3T was related to the members of the genus Kocuria. The highest 16S rRNA gene sequence similarity value was observed with Kocuria marina KMM 3905T (97.0 %). The peptidoglycan type of strain RS-2-3T was found to be A3α with an interpeptide bridge comprising l-Ala4-5. The predominant menaquinone was MK-7(H2) and the major fatty acids were anteiso-C15 : 0 and iso-C15 : 0. The DNA G+C content was 71.8 mol%. These characteristics were consistent with those of members of the genus Kocuria. Meanwhile, physiological and biochemical characteristics revealed that strain RS-2-3T differed from the species of the genus Kocuria with validly published names. Therefore, strain RS-2-3T represents a novel species of the genus Kocuria, for which the name Kocuria pelophila sp. nov. is proposed. The type strain is RS-2-3T (=NBRC 110990T=InaCC A704T).

Cellulosimicrobium marinum sp. nov., an actinobacterium isolated from sea sediment.

A novel Gram stain positive actinobacterium, designated RS-7-4(T), was isolated from a sea sediment sample collected in Indonesia, and its taxonomic position was investigated using a polyphasic approach. Strain RS-7-4(T) was observed to form vegetative hyphae in the early phase of growth, but the hyphae eventually fragmented into short rods to coccoid cells. Growth occurred at 15-37 °C, pH 6.0-11.0 and in the presence of 0-7 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain RS-7-4(T) was closely related to the members of the genus Cellulosimicrobium, with a similarity range of 98.08-99.10 %. The peptidoglycan type of strain RS-7-4(T) was found to be A4α L-Lys-L-Thr-D-Asp. The predominant menaquinone was MK-9(H4), and the major fatty acids were anteiso-C15:0, iso-C15:0 and anteiso-C17:0. The DNA G+C content was 75.6 mol%. These chemotaxonomic features corresponded to those of the genus Cellulosimicrobium. Meanwhile, the results of DNA-DNA hybridization, and physiological and biochemical tests revealed that strain RS-7-4(T) was different from the recognized species of the genus Cellulosimicrobium. Therefore, strain RS-7-4(T) represents a novel species of the genus Cellulosimicrobium, for which the name Cellulosimicrobium marinum sp. nov. is proposed. The type strain is RS-7-4(T) (=NBRC 110994(T) =InaCC A726(T)).

Actinoplanes bogoriensis sp. nov., a novel actinomycete isolated from leaf litter.

A novel actinomycete, designated LIPI11-2-Ac043(T), was isolated from leaf litter collected in Indonesia. According to phylogenetic analysis based on the 16S rRNA gene sequence comparisons, strain LIPI11-2-Ac043(T) was closely related to Actinoplanes abujensis A4029(T) (99.3%) and Actinoplanes brasiliensis DSM 43805(T) (98.8%). Spores of strain LIPI11-2-Ac043(T) were motile and the sporangia were spherical. The predominant menaquinone was MK-9(H6) and the principal polar lipids were phosphatidylinositol, phosphatidylethanolamine, phosphatidylglycerol and diphospatidylglycerol. The whole-cell sugars were galactose, glucose and mannose; rhibose, arabinose and xylose were also detected as minor components. The major fatty acids were anteiso-C15:0, iso-C16:0, iso-C15:0 and anteiso-C17:0. These data supported the affiliation of strain LIPI11-2-Ac043(T) to the genus Actinoplanes. Meanwhile, the results of DNA-DNA hybridization and physiological and biochemical tests indicated that strain LIPI11-2-Ac043(T) can be distinguished from its closest related species. Therefore, strain LIPI11-2-Ac043(T) represents a novel species of the genus Actinoplanes, for which the name Actinoplanes bogoriensis sp. nov. is proposed. The type strain is LIPI11-2-Ac043(T) (=InaCC A522(T)=NBRC 110975(T)).

Cryptosporangium cibodasense sp. nov., isolated from leaf litter in Indonesia.

A novel actinomycete strain, designated LIPI11-2-Ac046T, was isolated from a leaf litter sample obtained from Cibodas Botanical Garden, West Java, Indonesia, using the rehydration and centrifugation method. The taxonomic status of this organism was established using a polyphasic approach. Comparative 16S rRNA gene sequence analysis revealed that strain LIPI11-2-Ac046T had the closest sequence similarities with members of the genus Cryptosporangium (97.99-98.90 %). The strain grew well on ISP 4 and ISP 5 media and formed sporangia. Spores of this strain were motile. The strain grew in the presence of 0-2 % (w/v) NaCl and the temperature range of 15-28 8C. The cell-wall hydrolysate contained meso-diaminopimelic acid as the diagnostic diamino acid and the whole-cell hydrolysate contained mannose, glucose, galactose, ribose and xylose, together with one unidentified O-methyl-pentose. The predominant menaquinones were MK-9(H4), MK-9(H6) and MK-9(H8), and the major polar lipid was phosphatidylethanolamine. The major cellular fatty acids were C18 : 1ω9c, iso-C16 : 0, C16 : 0 andC17 : 1ω9c. These phenotypic characteristics corresponded to those of the genus Cryptosporangium. Meanwhile, the results of DNA-DNA hybridization as well as physiological and biochemical analyses distinguished strain LIPI11-2-Ac046T from known members of the genus Cryptosporangium. On the basis of these data, it is proposed that strain LIPI11-2-Ac046T represents a novel species of the genus Cryptosporangium, with the name Cryptosporangium cibodasense sp. nov. The type strain is LIPI11-2-Ac046T (=InaCC A457T=NBRC 110976T).

Actinoplanes tropicalis sp. nov. and Actinoplanes cibodasensis sp. nov., isolated from leaf litter.

Two actinomycete strains, designated LIPI11-2-Ac034T and LIPI11-2-Ac042T, were isolated from leaf litter collected from Cibodas Botanical Garden, West Java, Indonesia. Phylogenetic analysis based on 16S rRNA gene sequences suggested that both isolates belong to the genus Actinoplanes. These isolates were closely related to Actinoplanes ferrugineus and Actinoplanes durhamensis with similarity values of 98.2 % and 97.7 % respectively, for strain LIPI11-2-Ac034T, and 99.0 % and 97.4-97.7 % respectively for strain LIPI11-2-Ac042T. Both isolates grew well on ISP 7 medium with brown soluble pigment production. Spores were motile and sporangia were irregular. The isolates contained meso-diaminopimelic acid in cell-wall hydrolysates, and mannose, glucose and galactose in whole-cell hydrolysates. The predominant menaquinone of strain LIPI11-2-Ac034T was MK-9(H4) while that of strain LIPI11-2-Ac042T was MK-9(H6). The major cellular fatty acids were iso-C16 : 0, iso-C15 : 0 and anteiso-C15 : 0 for strain LIPI11-2-Ac034T, and iso-C16 : 0, anteiso-C15 : 0, iso-C15 : 0 and anteiso-C17 : 0 for strain LIPI11-2-Ac042T. Phosphatidylethanolamine was detected as the diagnostic polar lipid. The DNA G+C contents of strains LIPI11-2-Ac034T and LIPI11-2-Ac042T were 71.5 and 70.7 mol%, respectively. Based on the differential phenotypic characteristics and the results of DNA-DNA hybridization and phylogenetic analysis, it is proposed that strains LIPI11-2-Ac034T and LIPI11-2-Ac042T represent two novel species of the genus Actinoplanes, for which the names Actinoplanes tropicalis sp. nov. (type strain LIPI11-2-Ac034T = InaCC A459T = NBRC 110973T) and Actinoplanes cibodasensis sp. nov. (type strain LIPI11-2-Ac042T = InaCC A458T = NBRC 110974T) are proposed.

Tropicihabitans flavus gen. nov., sp. nov., a new member of the family Cellulomonadaceae.

Two novel Gram-stain positive actinobacteria, designated PS-14-16(T) and RS-7-1, were isolated from the rhizosphere of a mangrove and sea sediment, respectively, and their taxonomic positions were investigated by a polyphasic approach. Both strains were observed to form vegetative hyphae in the early phase of growth but the hyphae eventually fragment into short rods to coccoid cells. The peptidoglycan type of both strains was found to be A4α. Their predominant menaquinone was identified as MK-9(H4) and the major fatty acid as anteiso-C(15:0). The DNA G+C content was determined to be 68.4-68.5 mol%. 16S rRNA gene sequencing revealed that strains PS-14-16(T) and RS-7-1 were related to members of the family Cellulomonadaceae. Their nearest phylogenetic neighbour was found to be Sediminihabitans luteus, which is currently the only species of the genus Sediminihabitans, with a similarity of 97.94%. However, strains PS-14-16(T) and RS-7-1 were distinguishable from the members of the genus Sediminihabitans and the other genera within the family Cellulomonadaceae in terms of chemotaxonomic characteristics and phylogenetic relationship. The results of DNA-DNA hybridization experiments indicated that strains PS-14-16(T) and RS-7-1 belong to the same species. Strains PS-14-16(T) and RS-7-1 are concluded to represent a novel genus and species of the family Cellulomonadaceae, for which the name Tropicihabitans flavus gen. nov., sp. nov. is proposed. The type strain of T. flavus is PS-14-16(T) (=NBRC 110109(T) = IanCC A 516(T)). [corrected].

Serinibacter tropicus sp. nov., an actinobacterium isolated from the rhizosphere of a mangrove, and emended description of the genus Serinibacter.

A novel Gram-stain-positive actinobacterium, designated PS-14-7(T), was isolated from the rhizosphere of a mangrove on Pramuka Island, Indonesia, and its taxonomic position was investigated using a polyphasic approach. The peptidoglycan type of strain PS-14-7(T) was A4α and lysine was the diagnostic diamino acid of the peptidoglycan. The predominant menaquinone was MK-8(H4) and the major fatty acids were anteiso-C(15 : 0), C(16 : 0) and iso-C(16 : 0). The DNA G+C content was 72.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain PS-14-7(T) was closely related to Serinibacter salmoneus Kis4-28(T) (99.6%). However, DNA-DNA hybridization and phenotypic characteristics revealed that strain PS-14-7(T) differed from Serinibacter salmoneus . Therefore, strain PS-14-7(T) represents a novel species of the genus Serinibacter , for which the name Serinibacter tropicus sp. nov. is proposed. The type strain is PS-14-7(T) ( = NBRC 110108(T) = InaCC A 515(T)). An emended description of the genus Serinibacter is also proposed.

Actinophytocola timorensis sp. nov. and Actinophytocola corallina sp. nov., isolated from soil.

Two actinomycete strains, ID05-A0653(T) and ID06-A0464(T), were isolated from soils of West Timor and Lombok island, respectively, in Indonesia. 16S rRNA gene sequence analysis clearly demonstrated that the isolates belonged to the family Pseudonocardiaceae and were closely related to the genus Actinophytocola. Strains ID05-A0653(T) and ID06-A0464(T) exhibited 98.1 and 98.2 % 16S rRNA gene sequence similarity, respectively, with Actinophytocola oryzae GMKU 367(T). The isolates grew well on ISP media and produced white aerial mycelium. Short spore chains were formed directly on the substrate mycelium. The isolates contained meso-diaminopimelic acid, arabinose and galactose as cell-wall components, MK-9(H(4)) as the sole isoprenoid quinone, iso-C(16 : 0) as the major cellular fatty acid and phosphatidylethanolamine as the diagnostic polar lipid. The DNA G+C contents of strains ID05-A0653(T) and ID06-A0464(T) were 69.7 and 71.2 mol%, respectively. On the basis of phenotypic characteristics, DNA-DNA relatedness and 16S rRNA gene sequence comparisons, strains ID05-A0653(T) and ID06-A0464(T) each represent a novel species of the genus Actinophytocola, for which the names Actinophytocola timorensis sp. nov. (type strain ID05-A0653(T)  = BTCC B-673(T)  = NBRC 105524(T)) and Actinophytocola corallina sp. nov. (type strain ID06-A0464(T)  = BTCC B-674(T)  = NBRC 105525(T)) are proposed.

Dietzia timorensis sp. nov., isolated from soil.

An actinomycete strain, ID05-A0528(T), was isolated using the SDS-yeast extract pre-treatment method from soil under mahogany (Swietenia mahogani) trees in West Timor, Indonesia, and was examined by using a polyphasic taxonomic approach. Chemotaxonomic and phylogenetic characterizations demonstrated that the novel strain belongs to the genus Dietzia. 16S rRNA gene sequencing studies showed that the strain was related to Dietzia cinnamea (97.2 %). Results of phenotypic and phylogenetic analyses determined that strain ID05-A0528(T) is different from the known species of the genus Dietzia. It is proposed that the isolate should be classified as a representative of a novel species of the genus Dietzia, with the name Dietzia timorensis sp. nov. The type strain is ID05-A0528(T) (=BTCC B-560(T) =NBRC 104184(T)).

Actinokineospora baliensis sp. nov., Actinokineospora cibodasensis sp. nov. and Actinokineospora cianjurensis sp. nov., isolated from soil and plant litter.

Six actinomycete strains isolated from soil and plant-litter samples in Indonesia were studied for their taxonomic position by using a polyphasic approach. Phylogenetically, all the strains were located in the broad cluster of the genus Actinokineospora. Chemotaxonomic data [cell-wall diamino acid, meso-diaminopimelic acid; cell-wall peptidoglycan, type III (A1γ); major sugars, galactose and arabinose; major menaquinone, MK-9(H4); major fatty acid, iso-C16:0; major phospholipid, phosphatidylethanolamine] supported the affiliation of all six strains to the genus Actinokineospora. The results of DNA-DNA hybridization with DNA from type strains of Actinokineospora species with validly published names revealed three DNA-DNA relatedness groups. Group I (ID03-0561(T)) showed low relatedness to the other strains studied. The three strains in group II (ID03-0784(T), ID03-0808 and ID03-0809) formed a group with high relatedness (98-100 %) and showed low relatedness to the other strains studied. The two strains in group III (ID03-0810(T) and ID03-0813) showed 58-68 % relatedness to Actinokineospora terrae NBRC 15668(T) and showed low relatedness (2-24 %) to the other strains studied. The description of three novel species is proposed: Actinokineospora baliensis sp. nov., for the single strain in group I (type strain ID03-0561(T) =BTCC B-554(T) =NBRC 104211(T)), Actinokineospora cibodasensis sp. nov., for the strains in group II (type strain ID03-0784(T) =BTCC B-555(T) =NBRC 104212(T)), and Actinokineospora cianjurensis sp. nov., for the strains in group III (type strain ID03-0810(T) =BTCC B-558(T) =NBRC 105526(T)).

Streptomyces baliensis sp. nov., isolated from Balinese soil.

The taxonomic positions of actinomycete strains ID03-0915T and ID03-0825, isolated from soil on the Indonesian island of Bali, were examined using a polyphasic taxonomic approach. The morphological and chemotaxonomic characteristics of these organisms are typical of the genus Streptomyces. Phylogenetic analyses performed using almost-complete 16S rRNA gene sequences demonstrated that the strains were closely related to Streptomyces glauciniger and Streptomyces lilacinus. However, DNA-DNA hybridization and phenotypic characteristics revealed that the strains differed from known Streptomyces species. Therefore, we conclude that strains ID03-0915T and ID03-0825 (=BTCC B-563) represent a novel species of the genus Streptomyces, for which we propose the name Streptomyces baliensis sp. nov. The type strain is strain ID03-0915T (=BTCC B-608T=NBRC 104276T).