NCBI GenBank Accession Number Research Articles

Acaricidal effects of two native isolates of entomo-pathogenic bacteria Photorhabdus luminescens (Thomas & Poinar) against spider mite, Tetranychus truncatus Ehara (Acari: Tetranychidae)

ABSTRACTTwo local isolates of P. luminescens (NCBI GenBank Accession numbers ON627692, and ON627695) were evaluated for their bio-efficacy against the spider mite Tetranychus truncatus in the laboratory. Different concentrations (104 to 108 CS/CFS mL−1) of cell suspension (CS) and cell-free supernatant (CFS) of the bacterial isolates obtained by centrifugation (4000 rpm for 20 min) were topically applied on eggs and adults of spider mites. The observations on ovicidal as well as adulticidal activity of bacterial isolates were recorded at 24, 48, and 72 h intervals. The bacterial isolates showed significant ovicidal and adulticidal properties for both CS and CFS after 72 h of treatment application. The isolate CNT1 recorded 84.00 and 58.67% mortality of eggs and 100 and 97.33% mortality of adults, respectively, for CS and CFS, at 108 mL−1 concentration. At the same concentration, the isolate ODA showed 44.00 and 84.00% mortality of eggs and 98.67 and 100% mortality of adults, respectively, for CS and CFS. The study identified two bacterial isolates of P. luminescens with appreciable acaricidal properties that can be exploited as a potential biocontrol agent against spider mite pests of crops.

First report of tobacco rattle virus infecting Weigela florida in the USA.

Weigela (Weigela florida (Bunge) A. DC., Family: Caprifoliaceae) are woody shrubs native to North China, Korea, and Japan. In the U.S., weigela are commonly used as landscape ornamental plants (McNamara et al. 2010). Two viruses have been reported in weigela: tomato spotted wilt orthotospovirus and impatiens necrotic spot orthotospovirus (Sastry et al. 2019). Ten weigela plants, originating from commercial nurseries in Minnesota, exhibiting chlorosis, chlorotic line patterns, and necrosis (e-Xtra) were submitted for virus diagnostics as potted plants at the University of Minnesota Plant Disease Clinic and the Virology Lab in 2019 and 2020 (five plants each year). Under greenhouse conditions, symptoms progressed from chlorosis to necrosis and even plant death in two of the five plants in 2019. Electron microscopy revealed rod-shaped particles of ≈20 nm in diameter and lengths between 40-200 nm with similar morphology to members of the genus Tobravirus (e-Xtra). Virus-like particles were enriched by ultracentrifugation and total nucleic acids were extracted from partial purifications using a phenol:chloroform extraction method (Lockhart et al. 1997). Tobacco rattle virus (TRV) was identified by cloning and sequencing of the 463bp amplicon obtained with the TRV detection primers described in Robinson, 1992. High-throughput sequencing (HTS) was done to confirm the TRV detection. A cDNA library was prepared from purified viral RNA using the TruSeq Stranded mRNA kit and sequenced on Illumina NovaSeq 6000 platform as 150 bp-paired end reads. A total of 44,316,446 raw data reads were obtained, preprocessed using the BBDuk plugin, and de novo assembled using SPAdes assembler. Viral contigs were identified using the NCBI BLASTX tool. The assembly of TRV RNA1 was 6,842 nt with 20,627,348 reads (47% of total reads) mapped to it and an average coverage per nucleotide at 323,639X. The assembly of TRV RNA2 was 3,033 nt with 22,769,253 reads (52% of total reads) mapped to it and an average coverage per nucleotide at 798,660X. NCBI GenBank accession numbers for the assemblies representing RNA1 and RNA2 are OQ408335 and OQ408336, respectively. NCBI BLASTn analysis showed the highest level of nucleotide identity to TRV genomic RNA segments 1 and 2, with 97% and 99% identity to the TRV isolate RNA1 (GQ903771) and RNA2 (GQ903772), respectively, that originated from Michigan potato. No other viral contigs were detected from the virion nucleic acid extraction by HTS, however this enrichment method doesn't exclude other viruses. In addition to using the detection primers by Robinson 1992, we designed primers based on our HTS data: TRV-WG-DetF3 5'- GACGAAGGAGGCTGTCATTGC-3' and TRV-WG-DetR3 5'-CGGACTATCGTGATGCCCATGC- 3'. RT-PCR amplicons from each of the 10 symptomatic plants were cloned and sequenced. Among these clones, Sanger sequence identities ranged between 96-100% compared to the HTS data and 98-99% to the TRV potato isolate from MI. To our knowledge, this is the first report of TRV infecting the ornamental host W. florida worldwide. TRV is a nematode-transmitted viral pathogen of economic importance, most notably in potatoes (Sastry et al. 2019). In the US, TRV has been reported on several landscape ornamentals, horticultural crops, and native habitats. Further research is needed to investigate the impact of TRV on the ornamental industry and the role of ornamentals as reservoirs for cultivated crops like potatoes.

Biodegradation of Waste Lubricant Oil by a Novel Isolated Biosurfactant Producer- Achromobacter xylosoxidans PSA5

Waste lubricant oil (WLO) is a critical environmental issue because of its recycle and disposal challenges. A potent biosurfactant-producing bacterial strain was isolated by the enrichment culture technique using WLO as the sole carbon source from the oil-contaminated soils. The strain was identified as Achromobacter xylosoxidans (NCBI GenBank accession number: MW673656) based on the morphological, biochemical, and 16S rRNA gene sequencing. The preliminary characterization of the produced biosurfactant by biochemical methods revealed its glycolipid nature. The strain possessed extensive biodegradative potential and degraded various components present in WLO. The gas chromatography-mass spectrometry (GC-MS) analysis showed that the strain could degrade hydrocarbons (C7-C22) and diethyl phthalate, a priority pollutant, with a relative degradation of 43.87% within 7 days of incubation. The biodegradation of WLO by the strain confers its use in the bioremediation of oil-polluted environments, and the simultaneous biosurfactant production is undoubtedly a step toward greener technology.

Postharvest fruit rot of Bell pepper (Capsicum annuum L.): Pathogenicity and Host range of Alternaria alternata

Bell pepper is a fleshy vegetable cultivated in many countries. A severe fruit rot symptom was observed on green bell pepper in the local vegetable market in New Delhi, India. Fruit rot-associated fungal pathogen isolated on culture medium showed greyish-to-olive green mycelium with prolific conidial production. The pathogenicity test on green bell pepper indicated that inoculated fungus remained quiescent for ten days, triggering typical fruit rot upon the physiological maturation of bell pepper. Based on microscopic features and sequencing of genomic loci such as ITS, Alt a1, and RPB2, the pathogen identity was established as Alternaria alternata. Annotated nucleotides sequence of three genes were deposited and assigned NCBI GenBank accession numbers. Phylogenetic analysis using the taxonomic species of Alternaria strains revealed that the isolate A. alternata Cap_Aa clustered with reference strains of Alternaria alternata. A host range study of A. alternata Cap_Aa confirmed its pathogenicity on tomatoes and eggplant. Results presented in the present work provide knowledge on pathogen identity, host range, and genetic-relationship for developing suitable fruit rot management strategies and postharvest handling in the future.

OPTIMIZATION OF RIBOFLAVIN PRODUCTION USING BACILLUS CEREUS HDS07: A STRAIN ISOLATED FROM AGARICUS BISPORUS

The current study focused on the production and optimization of riboflavin from Bacillus cereus, a strain isolated from Agaricus bisporus. Seven different strains were isolated from Agaricus bisporus and screened for riboflavin production. Among the 7 strains, only 4 strains were identified as riboflavin producers by riboflavin assay medium (RAM). To determine the potency of the strains, selected strains were exposed to roseoflavin – an analogue of riboflavin. The potent strain was identified through morphological, biochemical, and molecular characterization and the strain name was designated as HDS07. Estimation of riboflavin was done by UV Spectrophotometry. Riboflavin production was done in Chemically Defined Medium (CDM) and De Man, Rogosa and Sharpe agar (MRS) using a strain Bacillus cereus HDS07. To enhance riboflavin production, the medium was optimized with different parameters like carbon, nitrogen sources, pH, temperature, and inoculum size. The potent strain HDS07 was identified as Bacillus cereus by 16S rDNA sequencing and NCBI-Gen Bank accession number - MK177597 was obtained. Riboflavin production from Bacillus cereus-HDS07 was more in the MRS medium than that of CDM. It was found to be 2.97 mg/L and 1.8 mg/L correspondingly. The maximum riboflavin (3.48 mg/L) was obtained from Bacillus cereus-HDS07 under the culture conditions; glucose, glycine, pH-6, 30℃, and 3% inoculum size. The current study emphasizes that the isolated potent strain Bacillus cereus-HDS07 from Agaricus bisporus could be used as a starter for the industrial production of riboflavin.

Isolation and Characterization of Beneficial Bacterium from the Rhizosphere of Suaeda nudiflora in Sundarbans, India

A study was carried out to isolate and characterize salt-tolerant beneficial bacteria from the soil collected from the rhizosphere of a halophytic plant (Suaeda nudiflora) from Gosaba, 24 Parganas (South), West Bengal, India located in the Sundarbans delta during January 2018. The physicochemical analysis of the soil showed that the soil was alkaline in nature with high salinity. The organic carbon, total nitrogen and available phosphorus status of the soil were low while the available potassium content was high. Bacterium N8 isolated from the rhizospheric soil possessed multiple growth-promoting activities i.e., the highest phosphate solubilizing efficiency (8.52 mg P g-1 of sugar), nitrogen-fixing capacity (0.7 mg of N g-1 of sugar), phosphatase enzyme activity and tolerance to salinity at 6% NaCl. A morphological study of this bacterium indicated that it was gram-positive, rod-shaped and was present in both single and chain form. The PCR amplification of genomic DNA (using 16S rDNA specific primers) showed a clear visible band at 1.5Kb. Sequencing of the amplicon followed by BLAST analysis depicted that the bacterium N8 exhibited the highest similarity (99%) with the genus Bacillus. The NCBI-Gen Bank accession number of the bacterium was SUB416213 N8 MH489431. The presence of members of the genus Bacillus in the rhizosphere soil of Suaeda nudiflora from Sundarbans is being reported for the first time. This study has led to a significant avenue for the use of the N8 bacterium as a potential salt-tolerant phosphate solubilizing bio-inoculum for improving nutrient availability in the coastal region.

Biofilm producing Bacillus vallismortis TR01K from tea rhizosphere acting as plant growth promoting agent

Microbial biofilms are an aggregation of single or multi-species bacteria that acquires the capacity to adhere to any surface where they can act like a wholesome system chemically “speaking with” each other through quorum sensing. This synergism is very prominently noticed in the rhizospheric regions of plant roots subsequently forming a dome which can protect the root-rhizospheric niche from various biotic and abiotic stress. The bacterial EPS have a number of roles like adhesion, cohesion and aggregation of soil particles, retaining water molecules, acts as a potential barrier on the rhizospheric regions, facilitating ionic and genetic information exchange within the matrix component, enhanced production of plant readily available nutrients etc. Keeping this scenario in mind, this study was formulated on to isolate and explore novel rhizobacteria with colossal biofilm forming ability showing great potential as a source of lignocellulolytic plant growth promoting agent.The crop chosen for this study was tea or Camellia sinensis, a quintessential beverage that is consumed across the globe. The rhizospheric region of a woody plant like tea, acts as a hub for lignocellulosic enzyme producing bacteria. The novel rhizobacteria isolated from cultivated tea soil, Bacillus vallismortis TR01K [NCBI Genbank Accession Number MT672714], was found to have an immense biofilm forming potential that ranged approximately 40x times higher than normal standard bacterial biofilm forming potentials when tested under laboratory conditions. Further in vitro characterizations of the novel strain showed it's immense potential to make plant nutrient available, to produce plant growth hormones (IAA, GA3, Cytokinin) and produce plant stress mitigating hormone (ACC deaminase). Lignocellulolytic enzymes are a vital part of lignocellulosic biomass degradation-a sustainable biotechnological approach for enzymes, organic acids, feed and biofuel production. The selected bacteria was tested elaborately for the family of lignocellulolytic enzymes (cellulase, laccase, lignin peroxidase, pectinase, amylase, chitinase, beta glucanase etc.) which showed promising results. Thus, proving the entire set of experiments in compliance with the aforementioned hypothesis that the novel bacterial isolate from tea rhizosphere has a significant biofilm forming potential with a colossal potency for being lignocellulolytic plant growth promoting agent.

First Report of Root-Knot Nematode Meloidogyne enterolobii Infecting Sweetpotato in the State of Rio Grande do Norte, Brazil.

The sweetpotato (Ipomoea batatas L., Convolvulaceae family) originated in Latin America and is currently cultivated worldwide. The storage roots, rich in calories, have made this crop one of the main caloric sources for low-income populations, especially in developing countries. Brazil annually produces about 805,000 tons, with the Northeast region responsible for 34% of this production (Albuquerque et al. 2020). In October 2019, sweetpotato plants cv. Campina, from a field in the region of Touros, state of Rio Grande do Norte (RN), Brazil (5°12'31"S 35°34'42"W), presented deformed storage roots, with galls, typical of root-knot nematodes. The roots were sent to the Nematology Laboratory (LabNema) where 14,032 eggs and 3,312 second-stage juveniles (J2s) of Meloidogyne sp., in 10 g of roots, were recovered. The species of adults was identified through morphological, biochemical, and phylogenetic analysis. The perineal region of females (n = 10) presented an oval shape, with a high and semi-trapezoidal dorsal arch and streak-free perivulval region. The labial region of males (n=10) presented high and rounded head cap, labial region slightly set off from the body, without annulations. The morphological characters were compatible with the original description of Meloidogyne enterolobii (Yang and Eisenback 1983). The phenotype of esterase isoenzymes showed two major bands (VS1-S1) also characteristic of M. enterolobii (Esbenshade and Triantaphyllou 1985). Sequences of 18S rDNA (~1200bp) of individual females (Holterman et al. 2006) obtained from sweetpotatoes before (SPme1 and 2) and after inoculation (SPme3 and 6), and from guava, used as M. enterolobii species control, were submitted to Bayesian analysis. The sequences presented genetic diversity among them resulting from seven SNPs (Single Nucleotide Polymorphism) and 99.4 to 99.9% identity with M. enterolobii sequences deposited in the NCBI GenBank (accession numbers MW209034-MW209039). The pathogenicity test was carried out under greenhouse conditions, in which 3,000 eggs and J2s from the original population isolated of M. enterolobii were inoculated in sweetpotato seedlings cv. Campina (n = 6). After three months, the roots presented galls and deformations typical of root-knot nematodes, while non-inoculated plants did not present any symptoms. An average of 15,900 eggs and J2s of M. enterolobii (RF = 5.3) were recovered from the roots, proving that sweetpotatoes were a host of this species. Meloidogyne enterolobii is known to cause great damage to sweetpotato (Ye et al. 2020). In Brazil, Meloidogyne nematode had been reported once, isolated from a sweetpotato field in the Ceara state and the species suggested by the authors according to esterase electrophoresis was M. enterolobii. Nonetheless, the authors did not present taxonomic, isoenzyme phenotypes and molecular species identification integratively, nor included pathogenicity tests (Silva et al. 2016). Therefore, it is the first time that M. enterolobii, with reliable identification by different methods, including sequencing, was detected in commercial sweetpotato fields in the RN state and in Brazil. The local farmers reported that this nematode deforms the storage roots which make them useless for commercialization, resulting in minimal losses of 50% of production in the infested areas. Furthermore, as sweetpotatoes are vegetatively propagated, the spread of this nematode through planting material is favored. Considering the importance of this crop in Brazil, this report is essential for control measures of this pathogen to be taken in order to avoid its spread to other regions.

Identification and pathogenicity of Plesiomonas shigelloides from Acipenser dabryanus in China

Acipenser dabryanus is designated as a critically endangered species on the IUCN Red List and known as a first-class protected animal in China. Recently, A. dabryanus fries (approximately 45 days old) in a fishery institute in south-western China suffered from a high rate of mortality. In this study, a strain of Plesiomonas shigelloides was isolated from the liver and heart of the infected fry, named 22S, and confirmed to be related to the mortality of A. dabryanus fries. Plesiomonas shigelloides was identified using biochemical characterization and molecular analysis. A 16S rDNA gene sequence alignment analysis found that the isolate shared 100% homology with P. shigelloides (NCBI GenBank Accession Number—NR 044827) in this gene. Antimicrobial susceptibility testing showed that 22S was resistant to penicillin, oxacillin, clindamycin, trimethoprim and lincomycin and sensitive to nitrofurantoin, levofloxacin tablets and norfloxacin. The LD50 value was 5.94*105 cfu/g. Clinical symptoms of challenged fish were the same as those of naturally infected fish. Histopathology of the infected fish showed that the viscera and gill were severely damaged. This is the first report suggesting that P. shigelloides infection is associated with mass mortality of A. dabryanus. The results of this study elucidate the pathogenesis and severe pathogenicity of P. shigelloides in cultured A. dabryanus and highlight the need for appropriate disease control and prevention measures.

Molecular Autograph of Maturase-K Gene in Isodon rugosus (Lamiaceae)

AbstractMolecular autograph of trn/mat-K gene was used as one of the important candidate marker in addressing the questions of systematics and barcoding of medicinal plants. Features of trn/mat-K gene in Isodon rugosus (Lamiaceae) were assessed for the first time (NCBI GenBank Accession Number: MH939199.1). Sequence of 756 bp length was amplified by the universal matK primers (matK472F and matK1248R) in the cpDNA of the plant. It was reported to contain trnK gene (>1…..50; >746…..756), partial sequence; and matK gene (>51…..745), partial coding DNA sequence. Alignment search and analysis showed that only nine different Isodon species are currently available for matK sequences with repeated copy of submissions in GenBank. The matK sequences of I. rugosus was reported with 34.2 (G + C)% and 17 variable sites (VS), out of which seven were singleton (ST) and 10 sites were species-specific parsimoniously-informative (PI) that could be used to differentiate I. rugosus from other species as well as to authenticate the taxon. Phylogenetic analysis resulted into monophyletic clustering of I. rugosus near to the clade having I. coetsa by both maximum likelihood (ML) and maximum parsimony (MP) methods. Clades obtained in ML tree were more informative as compared to MP tree.

Isolation and efficacy of native chitinolytic rhizobacteria for biocontrol activities against Fusarium wilt and plant growth promotion in pigeon pea (Cajanus cajan L.)

The present study aimed to identify, characterize, and evaluate native chitinolytic rhizobacteria as biocontrol potential against pigeon pea wilt disease, caused by Fusarium udum. A total of 53 isolated rhizobacteria was evaluated for their chitinolytic potential and possession of different antifungal traits. From the successive in vitro experiments and in vivo bioassay, 2 promising bacterial strains (NS-1 and NS-22) that exhibited strong chitinolytic activities and mycolytic action were biochemically characterized and identified as Pseudomonas spp. NS-1 (NCBI GenBank accession number- KT175909) and Bacillus spp. NS-22 (NCBI GenBank accession number-MH425454), using 16S rDNA sequencing. In planta, disease severities for Pseudomonas spp. NS-1- and Bacillus spp. NS-22-treated plants were only about 14.62 and 23.08%, respectively, as compared to pathogen-only control (67.34%) at the end of 4 weeks. Additionally, these bacteria improved plant germination and fresh and dry plant biomasses under pathogen-challenged conditions. Further, both the strains were able to cause a considerable amount of reduction in the fungal biomass, as revealed by bacteria-pathogen interaction studies in liquid culture. Scanning electron microscopy studies also revealed the strong antifungal activities of these 2 chitinolytic bacteria on the pathogen hyphae and mycelia. The curling, bulging, breakdown, and other dysfunctionalities in fungal hyphae were induced by the biocontrol bacteria. In nutshell, the present exclusive investigation demonstrated mycolytic potential and biocontrol prospects of the 2 promising bacteria (Pseudomonas spp. NS-1 and Bacillus spp. NS-22) for the sustainable Fusarium wilt management and as a phytostimulator in pigeon pea.

Epidemiology and molecular diagnosis of canine coronavirus in Egypt: evaluation of different tests used for its diagnosis

This work aimed to study the epidemiology and molecular detection of existing canine coronavirus (CCoV) strain circulating in Egypt. A total number of 86 dogs with clinical signs suggestive for CCoV infection was subjected to clinical examination and quick immunochromatography (IC) on faecal swabs to detect viral antigen. To identify CCoV viral RNA and S protein gene in blood and faeces, conventional PCR and quantitative RT-PCR were used. All examined dogs showed clinical signs suggestive of CCoV infection. Only 32 out of 86 dogs were positive for IC. Of all samples, 36 showed positive results in PCR and the amplification products from these 36 samples were confirmed as CCoV-S protein partial gene by the analysis of nucleotide sequence. However, the qRT-PCR analysis detected 45 positive samples e.g. more than those of IC or conventional polymerase chain reaction. Statistical evaluation of IC and conventional PCR to the results of qRT-PCR performance showed sensitivity, specificity, accuracy, positive and negative predictive values of 71%, 100%, 84.9%, 100%, 75.9% for IC and 80%, 100%, 89.5%, 100%, 82% for PCR, respectively. Sex and age had no effects on IC and PCR results. The prevalence of CCoV infection among the population of this study was 52.3%. Sequence analysis results proved that CCoV strain 59/08 was the strain, circulating in Egypt among dog populations. PCR products of the CCoV cDNA were closely identical to published CCoV-S partial gene. The NCBI Genbank accession number of sequence of the studied gene (CCoV-S partial gene) in this study was KY655745.

Molecular and phylogenetic study of Staphylococcus aureus isolated from human and cattle of Al-Qadisiyah Governorate, Iraq.

Aim:This study was designed to detect the prevalence of Staphylococcus aureus, to estimate the frequency of methicillin resistance gene (mecA), femA (specific gene for S. aureus), and lukS gene, and the prevalence of urinary tract infection (UTI) in human and bovine mastitis caused by S. aureus.Materials and Methods:A total of 102 cases of S. aureus were included in this study; 72 specimens were isolated from human with UTIs and 30 specimens were isolated from milk of cattle with acute mastitis. Diagnosis was done by VITEK 2 Compact after subculture and purification. All isolates were examined for the presence of mecA, femA, and lukS (Panton-Valentine leukocidin) using multiplex polymerase chain reaction.Results:Culture and biochemical evaluation of the samples revealed the presence of S. aureus, among which the genes mecA, femA, and lukS were positively detected in 68 (94.4%), 36 (50%), and 20 (27.7%) of S. aureus isolates from methicillin-resistant humans, respectively. In the same manner, the genes mecA, femA, and lukS were positively detected in 27 (90%), 14 (46.7%), and 11 (36.7%) of S. aureus isolates from methicillin-resistant cattle. Sequencing of partial order of femA gene isolated from human isolate and from cattle with mecA isolated from human revealed high sequence identity with the National Center for Biotechnology Information (NCBI)-Basic Local Alignment Search Tool. S. aureus isolates and the phylogenetic analysis showed that there was a significant genetic similarity (0.5 genetic change) between human and animals isolates, and then, the gene sequences were deposited into NCBI-Genbank accession numbers MG696860.1 for mecA and femA from human, MG696861.1 for mecA and femA from cattle, MK474469.1 for mecA and femA gene from human, and MG696862.1 for mecA and femA gene from cattle.Conclusion:The study represents the first report of genetic relationship between S. aureus from humans and cattle of Iraq. Therefore, it is essential to define the role of animals as an important source of the distribution of pathogen related to public health. The continuous monitoring of methicillin susceptibility pattern of S. aureus isolates that have high standards of infections might prevent methicillin-resistant S. aureus transmission in either direction between human and cattle, the risk of dairy milk on humans, or self-direction between the same species.

Flavobacterium sharifuzzamanii sp. nov., Isolated from the Sediments of the East China Sea.

A novel bacterial strain A7.6T was isolated from the sediments collected near the Zhairuo Island located in the East China Sea and characterized using a polyphasic approach. Cells were Gram-stain-negative, rod-shaped, non-spore forming, non-flagellated but motile by gliding. The strain was aerobic, positive for oxidase and catalase activities. The strain can grow at 4-35°C, pH 5.5-9.0, and 0-3% (w/v) NaCl concentration. The major polar lipid was phosphatidylethanolamine, the predominant fatty acids (> 10%) were iso-C15:0 and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c). The genomic G+C content was 33.6mol% and the major respiratory quinone was menaquinone 6. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain A7.6T belonged to the genus Flavobacterium and was closely related to Flavobacterium tistrianum GB 56.1T (98.4% similarity), F. nitrogenifigens NXU-44T (98.4%), F. ginsenosidimutans THG 01T (98.0%) and F. anhuiense D3T (97.7%). Average nucleotide identities and digital DNA-DNA hybridizations values for genomes ranged from 75.9 to 91.4% and 21.4 to 43.9% between strain A7.6T and its closest phylogenetic neighbors. The polyphasic characterization indicated that strain A7.6T represented a novel species of the genus Flavobacterium, for which the name Flavobacterium sharifuzzamanii is proposed. The type strain is A7.6T (= KCTC 62405T = MCCC 1K03485T). The NCBI GenBank accession number for the 16S rRNA gene of A7.6T is MH396692, and for the genome sequence is QJGZ00000000. The digital protologue database (DPD) Taxon Number is TA00643.

Sphingobium tyrosinilyticum sp. nov., a tyrosine hydrolyzing bacterium isolated from Korean radish garden.

A yellow-pigmented novel bacterial strain, MAH-12T, was isolated from a soil sample of Korean radish garden and was characterized using a polyphasic approach. Cells were Gram-staining negative, non-motile and rod-shaped. The strain was aerobic, catalase positive, optimum growth temperature and pH were 28-30°C and 6.0, respectively. The novel strain is able to hydrolyze L-tyrosine, starch, esculin and 4-nitrophenyl-β-D-galactopyranoside. On the basis of 16S rRNA gene sequence analysis, strain MAH-12T belongs to the genus Sphingobium and is most closely related to several Sphingobium type strains (97.2-97.8%). In DNA-DNA hybridization tests, the DNA relatedness between strain MAH-12T and its closest phylogenetic neighbors was below 45.0%. The DNA G + C content was 64.0mol% and the predominant respiratory quinone was ubiquinone-10. The major cellular fatty acids were summed feature 8 (C18:1 ω7c and/or C18:1 ω6c) and C16:0. The DNA-DNA hybridization results and results of the genotypic analysis in combination with chemotaxonomic and physiological data demonstrated that strain MAH-12T represented a novel species within the genus Sphingobium, for which the name Sphingobium tyrosinilyticum is proposed. The type strain is MAH-12T (= KACC 19297T = CGMCC 1.16225T). The NCBI GenBank accession number for the 16S rRNA gene sequence of strain MAH-12T is KY964278 and the digital protologue database taxon number of strain MAH-12T is TA00463.

Identification and pathogenicity of Plesiomonas shigelloides in Silver Carp

Plesiomonas shigelloides was isolated from diseased silver carp in Kolkata Wetland, West Bengal, India. It was associated with mortality of Silver Carp, Hypophthalmichthys molitrix, which is the most widely cultivable fish species in fresh water aquaculture. The P. shigelloides was identified based on the biochemical and molecular characterization and the pathogenicity was studied on H. molitrix. The 16S rRNA gene sequence of the present isolate (NCBI GenBank Accession Number- KX986915) revealed that, the isolate was 100% identical with P. shigelloides (NCBI GenBank Accession Number- MF100995). P. shigelloides killed 10–100% fish in experimental infection and the LD50 value was calculated as 1.3× 105CFU per fish with intraperitoneal injection. The challenged fish had subcutaneous haemorrhagic ulcers and reddening at injection sites, however there was no clinical sign observed in the gill. The histology of experimentally challenged H. molitrix showed the kidney alterations and exhibited shrinkage of epithelial cells in renal tubule and enlargement of glomerular cells.Liver showed focal accumulation of edematous fluid, necrosis and infiltration of heterophils indicative of bacterial infection. The pathology and pathogenesis studies of this pathogen in inland open waters like wetlands and lakes would help in management of the outbreak of disease in these aquatic ecosystems.

Characterization and optimization of a heterotrophic bacterium for sulfide degradation

The emission of hydrogen sulfide in the waste gas from slaughter plant, fishmeal feed processing and some other food industrial processing could cause serious air pollution to the surrounding environment. The purpose of this study was to screen heterotrophic bacterium strains for the removal of hydrogen sulfide odor. One heterotrophic bacterial mutant ZJNB-B3 was derived from the sulfide degrader Bacillus cereus XJ-2 and its sulfide removal efficiency was 97%. Based on the morphology studies, biochemical tests and 16S rRNA gene analysis, the strain was identified as Bacillus cereus ZJNB-B3. The NCBI GenBank accession number is MF679650. Batch tests showed that the strain tolerated up to 300 mg/L of toxic S²⁻ concentration. Response surface methodology was applied to optimize the conditions of degradation of sulfide. The optimal parameters were as follows: initial sulfide concentration 211.8 mg/L, initial pH 6.72, inoculum volume 5.04%, and incubation temperature 30 ℃. The accumulated sulfate concentration was 63.8 mg/L and the sulfide removal efficiency was 97.3% after 48 h incubation. No sulfuric acid was generated during sulfide oxidation by the strain. Sulfide could be removed effectively by this strain under mild pH conditions. The results suggested that the strain may have great industrial application potential. This study provides the fundamentals for the removal of hydrogen sulfide gas.

Flavobacterium chungangensis sp. nov., a Bacterium Isolated from Soil of Chinese Cabbage Garden.

A novel bacterial strain MAH-10T was isolated from soil sample of a Chinese cabbage garden, Republic of Korea and was characterized using a polyphasic approach. Cells were Gram-staining negative, rod-shaped, yellowish orange colored, and motile. The strain was aerobic, catalase and oxidase are positive, and optimum growth temperature and pH were 28°C and 6.5, respectively. Flexirubin-type pigments were found to be present. On the basis of 16S rRNA gene sequence analysis, strain MAH-10T belongs to the genus Flavobacterium and is most closely related to Flavobacterium tyrosinilyticum KCTC 42726T (98.7%). On the basis of phylogenetic tree, other closely related species are Flavobacterium banpakuense KACC 14225T (98.3%) and Flavobacterium chungbukense KACC 15048T (97.6%). In DNA-DNA hybridization tests, the DNA relatedness between strain MAH-10T and its closest phylogenetic neighbor was below 45.0%. The DNA G+C content was 37.2mol% and the predominant respiratory quinone was menaquinone-6. The major cellular fatty acids were C15:0 iso, C16:0, and summed feature 3 (C16:1ω7c and/or C16:1ω6c). On the basis of DNA-DNA hybridization results and genotypic, chemotaxonomic, and physiological data analysis, it is demonstrated that strain MAH-10T represented a novel species within the genus Flavobacterium, for which the name Flavobacterium chungangensis is proposed. The type strain is MAH-10T (=KACC 19296T=CGMCC 1.16226T). The NCBI GenBank accession number for the 16S rRNA gene sequence of strain MAH-10T is KY964277 and the digital protologue database (DPD) Taxon Number of strain MAH-10T is TA00296.

Chryseobacterium chungangensis sp. nov., a bacterium isolated from soil of sweet gourd garden.

A novel bacterial strain, named MAH-7T, was isolated from a soil sample of a Korean sweet gourd garden and was characterized using a polyphasic approach. Cells were Gram-staining negative, orange colored, non-motile and rod shaped. The strain was aerobic and catalase, oxidase positive, optimum growth temperature and pH were 28-30°C and 7.0, respectively. On the basis of 16S rRNA gene sequence analysis, strain MAH-7T belongs to the genus Chryseobacterium and is most closely related to Chryseobacterium formosense CC-H3-2T (97.96%) and Chryseobacterium zeae JM-1085T (97.19%). In DNA-DNA hybridization tests, the DNA relatedness between strain MAH-7T and its closest phylogenetic neighbors were below 45.0%. The DNA G+C content was 37.6mol% and the predominant respiratory quinone was menaquinone-6 (MK-6). Flexirubin-type pigments were found to be present. The major cellular fatty acids were C15:0 iso, C17:0 iso 3OH, C17:1 isoω9c and summed feature 3 (C16:1ω7c and/or C16:1ω6c). The DNA-DNA hybridization results and results of the genotypic analysis in combination with chemotaxonomic and physiological data demonstrated that strain MAH-7T represented a novel species within the genus Chryseobacterium, for which the name Chryseobacterium chungangensis is proposed. The type strain is MAH-7T (= KACC 19293T = CGMCC 1.16232T). The NCBI GenBank accession number for the 16S rRNA gene sequence of strain MAH-7T is KY964274.

Caenispirillum humi sp. nov., a bacterium isolated from the soil of Korean pine garden.

A novel bacterial strain MAH-8T was isolated from a soil sample of a Korean pine garden and was characterized using a polyphasic approach. Cells were Gram-staining negative, pinkish yellow colored, motile and vibrio-shaped. The strain was aerobic and catalase, oxidase positive, optimum growth temperature and pH were 28-30°C and 7.0, respectively. On the basis of 16S rRNA gene sequence analysis, strain MAH-8T belongs to the genus Caenispirillum and is most closely related to Caenispirillum bisanense KCTC 12839T (98.14%), Caenispirillum deserti KCTC 42064T (96.35%), and Caenispirillum salinarum JCM 17360T (95.76%). In DNA-DNA hybridization tests, the DNA relatedness between strain MAH-8T and its closest phylogenetic neighbor was below 45.0%. The DNA G + C content was 70.5mol% and the predominant respiratory quinone was ubiquinone-10. Flexirubin-type pigments were present and the major cellular fatty acids were C18:1 ω7c/C18:1 ω6c, C16:1 ω7c/C16:1 ω6c and C16:0. The results of DNA-DNA hybridization and genotypic analysis in combination with chemotaxonomic and physiological data demonstrated that strain MAH-8T represented a novel species within the genus Caenispirillum, for which the name Caenispirillum humi, is proposed. The type strain is MAH-8T (= KACC 19294T = CGMCC 1.16224T). The NCBI GenBank Accession Number for the 16S rRNA gene sequence of strain MAH-8T is KY964275.