Comparison of bacterial diversity in proglacial soil from Kafni Glacier,Himalayan Mountain ranges,India, with the bacterial diversity of other glaciers in the world

Two 16S rRNA gene clone libraries (KF and KS) were constructed using two soil samples (K7s and K8s) collected near Kafni Glacier, Himalayas. The two libraries yielded a total of 648 clones. Phyla Actinobacteria, Bacteroidetes, Chloroflexi Firmicutes, Proteobacteria, Spirochaetae, Tenericutes and Verrucomicrobia were common to the two libraries. Phyla Acidobacteria, Chlamydiae and Nitrospirae were present only in KF library, whereas Lentisphaerae and TM7 were detected only in KS. In the two libraries, clones belonging to phyla Bacteroidetes and Proteobacteria were the most predominant. Principal component analysis (PCA) revealed that KF and KS were different and arsenic content influenced the differences in the percentage of OTUs. PCA indicated that high water content in the K8s sample results in high total bacterial count. PCA also indicated that bacterial diversity of KF and KS was similar to soils from the Pindari Glacier, Himalayas; Samoylov Island, Siberia; Schrimacher Oasis, Antarctica and Siberian tundra. The eleven bacterial strains isolated from the above two soil samples were phylogenetically related to six different genera. All the isolates were psychro-, halo- and alkalitolerant. Amylase, lipase and urease activities were detected in the majority of the strains. Long chain, saturated, unsaturated and branched fatty acids were predominant in the psychrotolerant bacteria.     

冰川生态系统固碳微生物研究进展

[目的] 海南海口含有丰富的温泉资源,对温泉微生物多样性进行研究,有助于进一步开发和利用海南温泉微生物资源。[方法] 本文采用Illumina HiSeq高通量测序技术对海口3个温泉[海甸岛荣域温泉（S1）、火山口开心农场温泉（S2）和西海岸海长流温泉（S3）] 水样中微生物ITS序列和16S rRNA基因V3-V4区进行测序及生物信息学分析,探究海口市3个不同区域的温泉真菌多样性与细菌多样性。[结果] （1）α多样性分析表明,真菌群落中,S3 > S1 > S2,而在细菌群落中,S2 > S1 > S3。β多样性分析表明,3个温泉真菌群落和细菌群落组成差异皆显著。（2）分类分析表明,温泉真菌群落优势菌门为子囊菌门（Ascomycota）和担子菌门（Basidiomycota）,细菌群落优势菌门为变形菌门（Proteobacteria）、拟杆菌门（Bacteroidetes）、Thermi、硝化螺旋菌门（Nitrospirae）、绿菌门（Chlorobi）、厚壁菌门（Firmicutes）、绿弯菌门（Chloroflexi）、放线菌门（Actinobacteria）。（3）CCA（Canonical correspondence analysis）分析表明,3个温泉的真菌群落主要影响因子是温度,细菌群落主要影响因子是总磷。[结论] 海南省海口市温泉中含有丰富的微生物资源,其微生物群落组成受多种环境因子影响,且影响真菌和细菌的主要环境因子不同。     

Bacterial communities in sediments of the shallow Lake Dongping in China

Aims: The purpose of this study was to discuss how the environmental inputs and anthropogenic activities impact bacterial communities in the sediments of a shallow, eutrophic and temperate freshwater lake. Methods and Results: Sediment cores were collected from Lake Dongping, located in Taian, Shandong, China. All samples were processed within 4 h of collection. Total nitrogen, total phosphorus (TP), total organic carbon, ammonium nitrogen and nitrate nitrogen content of samples were measured by Kjeldahl determination, sulphuric acid–perchloric acid digestion and molybdenum blue colorimetry, potassium dichromate titration, Nessler’s reagent colorimetric and the phenol disulphonic acid colorimetric method, respectively. Seasonal and temporal diversity of sediment bacterial communities at six stations in Lake Dongping were investigated using molecular approaches (terminal restriction fragment length polymorphism and 16S rDNA clone libraries). Noticeable seasonal and temporal variations were observed in bacterial diversity and composition at all six stations. Sediment bacterial communities in Lake Dongping belonged to 16 phyla: Proteobacteria (including α‐Proteobacteria, β‐Proteobacteria, δ‐Proteobacteria, ε‐Proteobacteria, γ‐Proteobacteria), Acidobacteria, Planctomycetes, Bacteroidetes, Firmicutes, Verrucomicrobia, Nitrospira, Chloroflexi, Gemmatimonadetes, Chlorobi, Cyanobacteria, Deferribacteres, Actinobacteria, OP8, Spirochaetes and OP11. Members of β‐, δ‐ and γ‐Proteobacterial sequences were predominant in 11 of 12 clone libraries derived from sediment samples. Sediment samples collected at stations 1 and 4 in July had the greatest bacterial diversity while those collected at station 2 in October had the least diversity. TP concentration was significantly correlated with the distribution of bacterial communities. Conclusions: Our results suggested that different environmental nutrient inputs contribute to seasonal and temporal variations of chemical features and bacterial communities in sediments of Lake Dongping. TP concentration was significantly correlated with the distribution of bacterial communities. Significance and Impact of the Study: This study has an important implication for the optimization of integrated ecosystem assessment of shallow temperate freshwater lake and provides interesting information for the subsequent of the ecosystem.     

Rapid qualitative characterization of bacterial community in eutrophicated wastewater stabilization plant by T-RFLP method based on 16S rRNA genes

Waste stabilization ponds are a simple, low-cost extensive process for treating wastewater, and well adapted to low socio-economic conditions in developing countries where the microbial populations in these systems are not well characterized. The phylogenetic bacterial community structure within a Tunisian wastewater stabilization plant treating domestic wastewater was assessed by Terminal Restriction Fragment Length Polymorphism method targeting 16S rRNA genes and by the APLAUS+ software of the Microbial Community Analysis (MiCA) web based tool. The dimeric enzymatic digestion with HaeIII and HinfI restriction enzymes revealed high bacterial diversity within the plant where 11 bacterial phyla were identified. The total bacterial community structure includes bacteria catalysing nitrogen and phosphorus removal and bacteria involved in the sulfur cycle. The bacterial community was characterized by the dominance of Proteobacteria which was the most populous phylum (60%) followed by the Actinobacteria (20%), the Firmicutes (10.3%), the Bacteroidetes (2.3%), the Nitrospira (2.2%). Minor bacterial phyla groups occupied smaller fractions such as Chloroflexi, Deferribacteres and Verrumicrobia. T-RFLP analysis revealed also that The Proteobacteria phylum was characterized by the dominance of bacteria of The Gammaproteobacteria class.     

Characterization of Ni-resistant bacteria in the rhizosphere of the hyperaccumulator <Emphasis Type="Italic">Alyssum murale</Emphasis> by 16S rRNA gene sequence analysis

The diversity of 184 isolates from rhizosphere and bulk soil samples taken from the Ni hyperaccumulator Alyssum murale, grown in a Ni-rich serpentine soil, was determined by 16S rRNA gene analysis. Restriction digestion of the 16S rRNA gene was used to identify 44 groups. Representatives of each of these groups were placed within the phyla Proteobacteria, Firmicutes and Actinobacteria by 16S rRNA gene sequence analysis. By combining the 16S rRNA gene restriction data with the gene sequence analysis it was concluded that 44.6% (82/184) of the isolates were placed within the phylum Proteobacteria, among these 35.9% (66/184) were placed within the class α-Proteobacteria, and 20.7% (38/184) had 16S rRNA gene sequences indicative of bacteria within genera that form symbioses with legumes (rhizobia). Of the remaining isolates, 44.6% (82/184) and 5.4% (10/184) were placed within the phyla Actinobacteria and Firmicutes, respectively. No placement was obtained for a small number (10/184) of the isolates. Bacteria of the phyla Proteobacteria and Actinobacteria were the most numerous within the rhizosphere of A. murale and represented 32.1% (59/184) and 42.9% (79/184) of all isolates, respectively. The approach of using 16S rRNA gene sequence analysis in this study has enabled a comprehensive characterization of bacteria that predominate in the rhizosphere of A. murale growing in Ni-contaminated soil.     

Molecular identification and dynamics of microbial communities in reactor treating organic household waste

The prokaryotic diversity associated with organic household waste (OHW), leachate (start-up inoculum), and mesophilic anaerobic digestion processes in the degradation of OHW for 44 and 90 days was investigated using a culture-independent approach. Bacterial and archaeal 16S rRNA and mcrA gene clone libraries were constructed from community DNA preparations. Bacterial clones were affiliated with 13 phyla, of which Firmicutes, Proteobacteria, and Bacteroidetes were represented in all libraries, whereas Actinobacteria, Thermotogae, Lentisphaerae, Acidobacteria, Chloroflexi, Cyanobacteria, Synergistetes, Spirochaetes, Deferribacteres, and Deinococcus-Thermus were exclusively identified in a single library. Within the Archaea domain, the Euryarchaeota phylum was the only one represented. Corresponding sequences were associated with the following orders of hydrogenotrophic methanogens: Methanomicrobiales (Methanoculleus genus) and Methanobacteriales (Methanosphaera and Methanobacterium genera). One archaeal clone was not affiliated with any order and may represent a novel taxon. Diversity indices showed greater diversity of Bacteria when compared to methanogenic Archaea.     

Bacterial diversity of soil in the vicinity of Pindari glacier,Himalayan mountain ranges,India, using culturable bacteria and soil 16S rRNA gene clones

Three 16S rRNA gene clone libraries (P1L, P4L and P8L) were constructed using three soil samples (P1S, P4S and P8S) collected near Pindari glacier, Himalayas. The three libraries yielded a total of 703 clones. Actinobacteria, Firmicutes and Proteobacteria were common to the three libraries. In addition to the above P1L and P8L shared the phyla Acidobacteria, Bacteroidetes, Gemmatimonadetes and Planctomycetes. Phyla Chlamydiae, Chlorobi, Chloroflexi, Dictyoglomi, Fibrobacteres, Nitrospirae, Verrucomicrobia, candidate division SPAM and candidate TM7s TM7a phylum were present only in P1L. Rarefaction analysis indicated that the bacterial diversity in P4S and P8S soil samples was representative of the sample. Principal component analysis (PCA) revealed that P1S and P8S were different from P4S soil sample. PCA also indicated that arsenic content, pH, Cr and altitude influence the observed differences in the percentage of specific OTUs in the three 16S rRNA gene clone libraries. The observed bacterial diversity was similar to that observed for other Himalayan and non-polar cold habitats. A total of 40 strains of bacteria were isolated from the above three soil samples and based on the morphology 20 bacterial strains were selected for further characterization. The 20 bacteria belonged to 12 different genera. All the isolates were psychro-, halo- and alkalitolerant. Amylase and urease activities were detected in majority of the strains but lipase and protease activities were not detected. Long chain, saturated, unsaturated and branched fatty acids were predominant in the psychrotolerant bacteria.     

基于高通量测序的黄河三角洲4种人工林土壤细菌结构及多样性研究

为研究黄河三角洲不同人工林土壤细菌群落特征,应用高通量测序技术,比较分析了刺槐、榆树、白蜡、臭椿4种人工林土壤细菌结构及多样性,并结合土壤理化性质进行相关性分析。结果表明:人工林土壤中共有31门细菌;4种人工林土壤中酸杆菌门、变形菌门、放线菌门细菌以及刺槐、臭椿人工林土壤中硝化螺旋菌门细菌是土壤中的优势群落。不同人工林土壤中酸杆菌门、变形菌门、硝化螺旋菌门、芽单胞菌门、拟杆菌门、广古菌门、泉古菌门、蓝藻菌门细菌丰度差异显著。刺槐人工林土壤细菌多样性最高;白蜡人工林土壤细菌多样性最低。土壤pH、含水量、有机质含量与酸杆菌门细菌丰度呈显著负相关关系,土壤pH与变形菌门、硝化螺旋菌门、芽单胞菌门细菌丰度呈极显著正相关关系;土壤pH、有效磷含量与人工林细菌多样性呈显著正相关关系。以上研究结果表明,黄河三角洲不同人工林土壤细菌群落存在一定差异,土壤pH、含水量、有机质、有效磷含量是影响土壤细菌结构和多样性的主要土壤因素。     

Bacterial communities associated with the rhizosphere of pioneer plants (<Emphasis Type="Italic">Bahia xylopoda</Emphasis> and <Emphasis Type="Italic">Viguiera linearis</Emphasis>) growing on heavy metals-contaminated soils

In this study, the bacterial communities associated with the rhizospheres of pioneer plants Bahia xylopoda and Viguiera linearis were explored. These plants grow on silver mine tailings with high concentration of heavy metals in Zacatecas, Mexico. Metagenomic DNAs from rhizosphere and bulk soil were extracted to perform a denaturing gradient gel electrophoresis analysis (DGGE) and to construct 16S rRNA gene libraries. A moderate bacterial diversity and twelve major phylogenetic groups including Proteobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes, Chloroflexi, Firmicutes, Verrucomicrobia, Nitrospirae and Actinobacteria phyla, and divisions TM7, OP10 and OD1 were recognized in the rhizospheres. Only 25.5% from the phylotypes were common in the rhizosphere libraries and the most abundant groups were members of the phyla Acidobacteria and Betaproteobacteria (Thiobacillus spp., Nitrosomonadaceae). The most abundant groups in bulk soil library were Acidobacteria and Actinobacteria, and no common phylotypes were shared with the rhizosphere libraries. Many of the clones detected were related with chemolithotrophic and sulfur-oxidizing bacteria, characteristic of an environment with a high concentration of heavy metal-sulfur complexes, and lacking carbon and organic energy sources.     

Comparative analysis of biodiversity in the planktonic and biofilm bacterial communities in Lake Baikal

Bacterial communities of the water and the biofilm formed during five years on an artificial substrate in Lake Baikal were studied by the pyrosequencing of 16S rRNA gene fragments; taxonomic diversity of bacterial communities and differences in their structure were revealed. The biofilm community contained mainly representatives of three phyla: Cyanobacteria, Bacteroidetes, and Proteobacteria; the amounts of other groups were within 1%. Bacterial community of the plankton was more heterogeneous; along with the dominant phyla (Bacteroidetes, Actinobacteria, and Proteobacteria) 15% of the members were of the other phyla. The use of pyrosequencing allowed to reveal 35 bacterial phyla in Lake Baikal, some of which were identified for the first time; moreover, minor groups of microorganisms (including only several sequences), which were not earlier determined by other molecular methods were found.     

Phylogenetic diversity of microbial communities of the Posolsk Bank bottom sediments,Lake Baikal

Massive parallel sequencing (the Roche 454 platform) of the 16S rRNA gene fragments was used to investigate microbial diversity in the sediments of the Posolsk Bank cold methane seep. Bacterial communities from all sediment horizons were found to contain members of the phyla Actinobacteria, Bacteroidetes, Deinococcus-Thermus, Firmicutes, Nitrospirae, Chloroflexi, Proteobacteria, and the candidate phyla Aminicenantes (OP8) and Atribacteria (OP9). Among Bacteria, members of the Chloroflexi and Proteobacteria were the most numerous (42 and 46%, respectively). Among archaea, the Thaumarchaeota predominated in the upper sediment layer (40.1%), while Bathyarchaeota (54.2%) and Euryarchaeota (95%) were predominant at 70 and 140 cm, respectively. Specific migration pathways of fluid flows circulating in the zone of gas hydrate stability (400 m) may be responsible for considerable numbers of the sequences of Chloroflexi, Acidobacteria, and the candidate phyla Aminicenantes and Atribacteria in the upper sediment layers and of the Deinococcus-Thermus phylum in deep bottom sediments.     

普洱地区茶叶内生细菌与根际土壤细菌群落结构分析

[目的]茶叶内生细菌、根际土壤细菌在普洱茶的发酵中起着重要的作用,还可以促进茶树生长,诱导茶树抗病性.研究其群落结构组成及相互关系可为微生物资源开发利用提供理论依据.[方法]本研究以普洱地区茶树叶片和根际土壤为材料,采用高通量测序技术,对茶叶及根际土壤细菌的16S核糖体RNA基因(16S rRNA)进行测序,比较分析茶...     

Diversity and Community Structure of Primary Wood-Inhabiting Bacteria in Boreal Forest

DNA-based pyrosequencing analysis of the V1- V3 16S rRNA gene region was used to identify bacteria community and shift during early stages of wood colonization in boreal forest soils. The dataset comprised 142,447 sequences and was affiliated to 11 bacteria phyla, 25 classes and 233 genera. The dominant groups across all samples were Proteobacteria, followed by Bacteroidetes, Acidobacteria, Actinobacteria, Amatimonadetes, Planctomycetes and TM7 group. The community structure of the primary wood-inhabiting bacteria differed between types of forest soils and the composition of bacteria remained stable over prolonged incubation time. The results suggest that variations in soil bacterial community composition have an influence on the wood-inhabiting bacterial structure.     

Microbial diversity in Tunisian geothermal springs as detected by molecular and culture-based approaches

Prokaryotic diversities of 12 geothermal hot springs located in Northern, Central and Southern Tunisia were investigated by culture-based and molecular approaches. Enrichment cultures for both aerobic and anaerobic microorganisms were successfully obtained at temperatures ranging from 50 to 75°C. Fourteen strains including four novel species were cultivated and assigned to the phyla Firmicutes (9), Thermotogae (2), Betaproteobacteria (1), Synergistetes (1) and Bacteroidetes (1). Archaeal or universal oligonucleotide primer sets were used to generate 16S rRNA gene libraries. Representative groups included Proteobacteria, Firmicutes, Deinococcus-Thermus, Thermotogae, Synergistetes, Bacteroidetes, Aquificae, Chloroflexi, candidate division OP9 in addition to other yet unclassified strains. The archaeal library showed a low diversity of clone sequences belonging to the phyla Euryarchaeota and Crenarchaeota. Furthermore, we confirmed the occurrence of sulfate reducers and methanogens by amplification and sequencing of dissimilatory sulfite reductase (dsrAB) and methyl coenzyme M reductase α-subunit (mcrA) genes. Altogether, we discuss the diverse prokaryotic communities arising from the 12 geothermal hot springs studied and relate these findings to the physico-chemical features of the hot springs.     

Molecular Analyses of the Microbial Community Composition of an Anoxic Basin of a Municipal Wastewater Treatment Plant Reveal a Novel Lineage of Proteobacteria

A culture-independent molecular phylogenetic approach was used to study prokaryotic diversity in an anoxic activated sludge from a municipal wastewater treatment plant. Two 16S rRNA gene libraries were constructed using total genomic DNA and amplified by polymerase chain reaction using primers specific for archaeal or bacterial domains. Phylogenetic analysis of 132 and 249 almost full-length 16S rRNA genes for Archaea and Bacteria, respectively, was done using the ARB software package. Phylogenetic groups affiliated with the Archaea belong to Euryarchaeota (93.8% of the operational taxonomic units [OTUs]) and Crenarchaeota (6.2% of the OTUs). Within the bacterial library, 84.8% of the OTUs represent novel putative phylotypes never described before and affiliated with ten divisions. The Proteobacteria phylum is the most abundant and diversified phylogenetic group representing 60.4% of the OTUs, followed by Bacteroidetes (22.1%) and gram-positives (6.1%). Interestingly, we detected a novel Proteobacteria monophyletic group distinct from the five known subclasses, which we named New Lineage of Proteobacteria (NLP) lineage, and it is composed of eight clones representing 4.6% of the Proteobacteria. A new 16S rRNA-targeted hybridization probe was designed and fluorescent in situ hybridization analyses shows representatives of NLP as cocci-shaped microorganisms. The Chloroflexi, Acidobacterium, and Nitrospira phyla and TM7 candidate division are each represented by ≤3% of clone sequences. A comprehensive set of eight 16S and 23S rRNA-targeted oligonucleotide probes was used to quantify these major groups by dot blot hybridization within 12 samples. The Proteobacteria accounted for 82.5 ± 4.9%, representing the most abundant phyla. The Bacteroidetes and Planctomycetales groups accounted for 4.9 ± 1.3% and 4 ± 1.7%, respectively. Firmicutes and Actinobacteria together accounted for only 1.9 ± 0.5%. The set of probes covers 93.4 ± 14% of the total bacterial population rRNA within the anoxic basin.     

Proteobacteria and Bacteroidetes are major phyla of filterable bacteria passing through 0.22 μm pore size membrane filter,in Lake Sanaru,Hamamatsu, Japan

141 filterable bacteria that passed through a 0.22 μm pore size filter were isolated from Lake Sanaru in Hamamatsu, Japan. These belonged to Proteobacteria, Bacteroidetes, Firmicutes, or Actinobacteria among which the first two phyla comprised the majority of the isolates. 48 isolates (12 taxa) are candidates assignable to new bacterial species or genera of Proteobacteria or Bacteroidetes.     

不同季节冬水田紫色土细菌群落的垂直分布规律

【背景】土壤细菌对环境变化非常敏感,是土壤环境质量检测的重要指标。【目的】为研究不同季节冬水田紫色土细菌的垂直分布规律,揭示土壤细菌群落结构和物种多样性与土壤环境因子的相互关系。【方法】以冬水田紫色土为研究对象,分别于2020年8月(夏季)和2021年 1月(冬季)采集不同深度土壤样品,对土壤细菌16S rRNA基因进行Illumina MiSeq高通量测序,分析在不同季节细菌群落组成和多样性的垂直分布规律。【结果】冬水田紫色土细菌ACE指数、Chao1指数和Shannon指数均呈现出夏季高于冬季,并且随土层深度增加呈现降低的趋势。冬水田紫色土优势菌门为变形菌门(Proteobacteria)、绿弯菌门(Chloroflexi)、酸杆菌门(Acidobacteria)、硝化螺旋菌门(Nitrospirae)、放线菌门(Actinobacteria)和浮霉菌门(Planctomycetes),优势菌属为Desulfobacca、Haliangium、Anaeromyxobacter、Candidatus_Omnitrophus和Defluviicoccus。Chloroflexi和Actinobacteria在夏季相对丰度较高,Proteobacteria和Nitrospirae在冬季相对丰度较高;Anaeromyxobacter和Candidatus_Omnitrophus在夏季相对丰度较高,Desulfobacca、Haliangium和Defluviicoccus在冬季相对丰度较高。冗余分析(redundancy analysis,RDA)和环境因子热图分析结果均表明,总氮(total nitrogen,TN)、土壤有机质(soil organic matter,SOM)和土壤氧化还原电位(soil redox potential,Eh)是显著影响紫色水稻土细菌群落的主要因子。【结论】本研究丰富了对冬水田紫色水稻土细菌群落组成和多样性的认识,证实了不同季节冬水田紫色土细菌群落组成和多样性存在差异。     

Diversity of bacterial community in freshwater of Woopo wetland

Diversity of bacterial community in water layer of Woopo wetland was investigated. Cultivable bacterial strains were isolated by the standard dilution plating technique and culture-independent 16S rRNA gene clones were obtained directly from DNA extracts of a water sample. Amplified rDNA restriction analysis (ARDRA) was applied onto both of the isolates and 16S rRNA gene clones. Rarefaction curves, coverage rate and diversity indices of ARDRA patterns were calculated. Representative isolates and clones of all the single isolate/clone phylotype were partially sequenced and analyzed phylogenetically. Sixty-four and 125 phylotypes were obtained from 203 bacterial isolates and 235 culture-independent 16S rRNA gene clones, respectively. Bacterial isolates were composed of 4 phyla, of which Firmicutes (49.8%) and Actinobacteria (32.0%) were predominant. Isolates were affiliated with 58 species. Culture-independent 16S rRNA gene clones were composed of 8 phyla, of which Proteobacteria (62.2%), Actinobacteria (15.5%), and Bacteroidetes (13.7%) were predominant. Diversity of 16S rRNA gene clones originated from cultivation-independent DNA extracts was higher than that of isolated bacteria.     

Isolation and Analysis of Bacteria with Antimicrobial Activities from the Marine Sponge Haliclona simulans Collected from Irish Waters

Samples of the marine sponge Haliclona simulans were collected from Irish coastal waters, and bacteria were isolated from these samples. Phylogenetic analyses of the cultured isolates showed that four different bacterial phyla were represented; Bacteriodetes, Actinobacteria, Proteobacteria, and Firmicutes. The sponge bacterial isolates were assayed for the production of antimicrobial substances, and biological activities against Gram-positive and Gram-negative bacteria and fungi were demonstrated, with 50% of isolates showing antimicrobial activity against at least one of the test strains. Further testing showed that the antimicrobial activities extended to the important pathogens Pseudomonas aeruginosa, Clostridium difficile, multi-drug-resistant Staphylococcus aureus, and pathogenic yeast strains. The Actinomycetes were numerically the most abundant producers of antimicrobial activities, although activities were also noted from Bacilli and Pseudovibrio isolates. Surveys for the presence of potential antibiotic encoding polyketide synthase and nonribosomal peptide synthetase genes also revealed that genes for the biosynthesis of these secondary metabolites were present in most bacterial phyla but were particularly prevalent among the Actinobacteria and Proteobacteria. This study demonstrates that the culturable fraction of bacteria from the sponge H. simulans is diverse and appears to possess much potential as a source for the discovery of new medically relevant biological active agents.     

Bacterial microbiome of Coptotermes curvignathus (Isoptera: Rhinotermitidae) reflects the coevolution of species and dietary pattern

Coptotermes curvignathus Holmgren is capable of feeding on living trees. This ability is attributed to their effective digestive system that is furnished by the termite's own cellulolytic enzymes and cooperative enzymes produced by their gut microbes. In this study, the identity of an array of diverse microbes residing in the gut of C. curvignathus was revealed by sequencing the near‐full‐length 16S rRNA genes. A total of 154 bacterial phylotypes were found. The Bacteroidetes was the most abundant phylum and accounted for about 65% of the gut microbial profile. This is followed by Firmicutes, Actinobacteria, Spirochetes, Proteobacteria, TM7, Deferribacteres, Planctomycetes, Verrucomicrobia, and Termite Group 1. Based on the phylogenetic study, this symbiosis can be a result of long coevolution of gut enterotypes with the phylogenic distribution, strong selection pressure in the gut, and other speculative pressures that determine bacterial biome to follow. The phylogenetic distribution of cloned rRNA genes in the bacterial domain that was considerably different from other termite reflects the strong selection pressures in the gut where a proportional composition of gut microbiome of C. curvignathus has established. The selection pressures could be linked to the unique diet preference of C. curvignathus that profoundly feeds on living trees. The delicate gut microbiome composition may provide available nutrients to the host as well as potential protection against opportunistic pathogen.