BACTERIAL PROFILES OF KARVACHAR HOT SPRING IDENTIFIED BY COMBINATION OF DIFFERENT MOLECULAR APPROACHES

Molecular techniques, including denaturing gradient gel electrophoresis (DGGE), 16S rRNA genes clone library construction and metagenomic analysis, were used to describe the bacterial composition of the Karvachar geothermal spring. It was shown the predominance of bacteria belonging to the phyla Proteobacteria, Bacteroidetes, Firmicutes and Cyanobacteria in the studied spring. Representatives of phylum Firmicutes were not detected in the clone library, while DGGE profiling and metagenome analysis confirmed the presence of Firmicutes as one of the major components in the bacterial community.

A Clone Resource of Magnaporthe oryzae Effectors That Share Sequence and Structural Similarities Across Host-Specific Lineages

The blast fungus Magnaporthe oryzae (syn. Pyricularia oryzae) is a destructive plant pathogen that can infect about 50 species of both wild and cultivated grasses, including important crops such as rice and wheat. M. oryzae is composed of genetically differentiated lineages that tend to infect specific host genera. To date, most studies of M. oryzae effectors have focused on the rice-infecting lineage. We describe a clone resource of 195 effectors of Magnaporthe species predicted from all the major host-specific lineages. These clones are freely available as Golden Gate–compatible entry plasmids. Our aim is to provide the community with an open source effector clone library to be used in a variety of functional studies. We hope that this resource will encourage studies of M. oryzae effectors on diverse host species.

Geographical Isolation, Buried Depth, and Physicochemical Traits Drive the Variation of Species Diversity and Prokaryotic Community in Three Typical Hypersaline Environments

The prokaryotic community composition, species diversity and the distribution patterns at various taxonomic levels in a salt lake (Chaka salt lake), solar salterns (Taipei saltworks and Dongfang saltworks), and salt mines (Yuanyongjing salt mine, Xiangyan salt mine, and Dinyuan salt mine) were investigated using clone library or Illumina MiSeq sequencing. The clone library approach revealed that the salt lake harbors low species diversity (H’ = 0.98) as compared to the solar saltern (H’ = 4.36) and salt mine (H’ = 3.57). The dominant group in the salt lake is a species from the genus Haloparvum which constitutes about 85% of the total sequences analyzed. The species diversities in salt salterns and salt mines are richer than in the salt lake, and the dominant group is less significant in terms of total percentage. High-throughput sequencing showed that geographical isolation greatly impacted on the microbial community (phyla level) and species diversity (operational taxonomic units (OTUs) level) of salt mines. Species of the genus Natronomonas are found in all three types of environments investigated. In addition, the microbial community and species diversity of different stratums of the salt mine are very similar. Furthermore, species of the genus Halorubrum flourish in the newest stratum of salt mine and have become the dominant group. This study provides some new knowledge on the species diversity and prokaryotic community composition of three typical hypersaline environments.

Functional modulation of caecal fermentation and microbiota in rat by feeding bean husk as a dietary fibre supplement

A feeding study using rats was conducted to evaluate the utility of lablab bean husk and soya bean husk as sources of potential prebiotic fibre. Twenty 5-week-old Sprague Dawley rats were divided into 4 groups and fed one of the following diets for 3 weeks: purified diet (AIN93 G) containing 5% cellulose (CEL), or the same diet in which cellulose was replaced by corn starch (STA), lablab bean husk (LBH), or soya bean husk (SBH). Rats were sacrificed at 8 weeks of age and caecal digesta were collected. Feed intake, body weight, anatomical parameters, and caecal ammonia level did not differ significantly among diets. Rats on LBH and SBH showed higher concentrations of caecal short-chain fatty acid and lactate than those on CEL. Rats on CEL, SBH, and LBH exhibited lower caecal indole and skatole levels. LBH yielded increased caecal abundance of Akkermansia muciniphila and Oscillibacter relatives, as demonstrated by either qPCR, MiSeq, or clone library analysis. SBH favoured the growth of lactobacilli as assessed by both qPCR and MiSeq, and favoured the growth of bifidobacteria as assessed by MiSeq. In comparison with STA, LBH and SBH yielded lower caecal abundance of bacteria related to Dorea massiliensis, as demonstrated by qPCR, MiSeq, and clone library analysis. Both types of bean husk were found to contain oligosaccharides that might selectively stimulate the growth of beneficial bacteria. Based on these results, the two species of bean husk tested are considered potentially functional for promoting the gut health of monogastric animals.

CLONING OF GENES ENCODING TRANSMEMBRANE PROTEINS AND PROTEINS RESPONSIBLE FOR AFRICAN SWINE FEVER VIRUS VIRULENCE

Results of cloning X69R, A179L, E248R, I215L and DP96R genes of ASF virus Krasnodar 07/17 isolate and analysis of their nucleotide sequences are presented. Obtained clones were added to the previously constructed clone library comprising clones of 8 genes of Krasnodar 06/12 isolate. Clones containing X69R, A179L, E248R, I215L and DP96R genes of ASF virus Krasnodar 07/17 isolate will be used for recombinant protein obtaining and testing for their effect on in vitro virus reproduction and their role in the virus infectivity, level of clinical manifestations and virulence. Prokaryotic vector, pJET1.2/ blunt, was used. Thus, the clone library available at the FGBI “ARRIAH” Reference Laboratory for African swine fever was supplemented by pJET1.2-X69R, pJET1.2-A179L, pJET1.2-E248R, pJET1.2-I215L and pJET1.2-DP96R plasmid constructions containing 5 genes of ASF virus Krasnodar 07/17 isolate. Proportion of cloned virus genes was 3.01% of Krasnodar 07/17 isolate genome, hence, total amount of the clone library has reached 7.82%.

CLONING OF GENES ENCODING TRANSMEMBRANE PROTEINS AND PROTEINS RESPONSIBLE FOR AFRICAN SWINE FEVER VIRUS VIRULENCE

Results of cloning X69R, A179L, E248R, I215L and DP96R genes of ASF virus Krasnodar 07/17 isolate and analysis of their nucleotide sequences are presented. Obtained clones were added to the previously constructed clone library comprising clones of 8 genes of Krasnodar 06/12 isolate. Clones containing X69R, A179L, E248R, I215L and DP96R genes of ASF virus Krasnodar 07/17 isolate will be used for recombinant protein obtaining and testing for their effect on in vitro virus reproduction and their role in the virus infectivity, level of clinical manifestations and virulence. Prokaryotic vector, pJET1.2/ blunt, was used. Thus, the clone library available at the FGBI “ARRIAH” Reference Laboratory for African swine fever was supplemented by pJET1.2-X69R, pJET1.2-A179L, pJET1.2-E248R, pJET1.2-I215L and pJET1.2-DP96R plasmid constructions containing 5 genes of ASF virus Krasnodar 07/17 isolate. Proportion of cloned virus genes was 3.01% of Krasnodar 07/17 isolate genome, hence, total amount of the clone library has reached 7.82%.

Identification of the Dominant Microbial Species of Spoiled Crisp Grass Carp (Ctenopharyngodon idellus C. et V.) and Grass Carp (Ctenopharyngodon idellus) Fillets during Cold Storage by Culture-Independent 16S rDNA Sequence Analysis

ABSTRACT A new freshwater cultivation species, crisp grass carp (CGC; Ctenopharyngodon idellus C. et V.) has a special texture and is popular with consumers; thus, we should pay close attention to its storage conditions and bacterial degradation. CGC and grass carp (GC; Ctenopharyngodon idellus) were commercialized as fillets and subsequently stored at 4 and 8°C. Microbial growth parameters (total viable counts, psychrotrophic bacteria, and Pseudomonas spp.), physicochemical data (pH and total volatile base nitrogen), and sensory analysis were monitored during the storage period. Dominant microorganisms were identified using a 16S rDNA clone library and restriction fragment length polymorphism (RFLP) analysis after the fillets had spoiled completely. The results showed that Pseudomonas spp. lagged behind the psychrotrophic population and the total viable counts initially and increased more rapidly after storage for 2 days. Total volatile base nitrogen contents were found to increase with storage time in both species, coinciding with ongoing microbial change. The pH results obtained for both species during storage showed an overall increase at the end of storage. Sensory evaluation showed a shelf life of 3 and 6 days for both species at 8 and 4°C, respectively. RFLP analysis of the 16S rDNA clone library revealed that there were seven and five distinct RFLP pattern groups in the microflora of the spoiled CGC and GC fillets, respectively. Through RFLP patterns and 16S rDNA sequencing from the clones, it was determined that CGC fillets stored at 4°C were dominated by Pseudomonas spp. at the point of sensory rejection, whereas GC fillets were dominated by populations affiliated with Pseudomonas sp., Acinetobacter sp., and Aeromonas sp.