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Vibriosis accounts for 66.7% of diseases reported in groupers' cultures and affects almost all stages of growth. The disease could lead up to mortality up to 50% mortality, and it was reported that high stocking density and poor fish handling were among the factors that contributed to the disease dissemination. V. harveyi has been reported to be among the causative agent and has caused acute mortality in cage groupers. In this study, we report the genome of V. harveyi VH1 isolated from a diseased tiger grouper Epinephelus fuscoguttatus, reared in a cage farm located in the coastal area of Langkawi. (c) 2022 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

A hypervirulent pathotype of A. hydrophila (vAh) is responsible for Motile Aeromonas Septicemia (MAS) and causes mass mortalities among farmed carp and catfish species in the USA and China. One unique phenotype for vAh among other A. hydrophila strains is the ability to utilize myo-inositol as a sole carbon source. While screening for Aeromonas isolates from diseased fish that can grow using myo-inositol as a sole carbon source, A. dhakensis 1P11S3 was isolated from the spleen of striped catfish (Pangasianodon hypopthalmus) displaying clinical MAS symptoms from a freshwater farm in Malaysia. Aeromonas dhakensis is also an important pathogen in aquaculture, and in this study, we report the draft genome sequence for A. dhakensis 1P11S3, that utilize myo-inositol as a sole carbon source.

Endophytic lactic acid bacteria (LAB) isolated from papaya seeds, including a consortium of two LAB isolates, Weissella cibaria PPKSD19 and Lactococcus lactis subsp. lactis PPSSD39 could previously inhibit papaya dieback disease causative agent, Erwinia mallotivora BT-MARDI in vitro, indicating their potential as biofertilizer. However, further characterizations on other plant growth-promoting (PGP) properties of the LABs are prerequisite to use in agricultural settings as bio-inoculum. Hence, this study aimed to evaluate PGP potentials further and in vitro antifungal activity of the LABs against various plant pathogens. The LAB isolates were tested positive in indole-3-acetic acid (IAA), siderophore, and ammonia production and could solubilize phosphate. Weissella cibaria PPKSD19 and L. lactis subsp. lactis PPSSD39 exhibited the strongest in vitro antifungal activity against Fusarium oxysporum TKA and Curvularia lunata. Inoculum concentration of 1x10 cfu/ml of W. cibaria PPKSD19 and L. lactis subsp. lactis PPSSD39 mixture showed the highest increment in shoot and root dry weight. In conclusion, W. cibaria PPKSD19 and L. lactis subsp. lactis PPSSD39 consortium displayed promising plant probiotic potential. These results highlighted the possibility of the bacterial consortium to be exploited as bioinoculant to promote plant growth and inhibit phytopathogens causing plant diseases.

Used cooking oil (UCO) is a hydrocarbon that causes significant environmental pollution globally. Oil is a difficult pollutant to remove from the environment due to its hydrophobic nature. Bioremediation is preferred over chemical and physical remediation approaches as it is more economical and environmentally friendly. Hence, the search for a microbe with outstanding degrading capability is imperative due to the nature of hydrocarbons as pollutants. The current study evaluates the ability of glyphosate degrader isolates, Burkholderia vietnamiensis AQ5-12 and Burkholderia sp. AQ5-13, to degrade UCO as the sole carbon source. The physico-cultural conditions affecting the activities of the isolates were studied using one-factor-at-a-time (OFAT) and response-surface methodology (RSM). The temperature, agitation speed, UCO concentration, nitrogen supply, yeast extract concentration, and inoculum size were optimised during a 7-day incubation period. Based on the OFAT results, the highest degradations were 62.23% and 58.33% for the isolates AQ5-12 and AQ5-13, respectively. The optimisation of RSM showed 83.42% and 87.09% degradation of the UCO by the AQ5-12 and AQ5-13 isolates. Parameters including the temperature, yeast extract, and ammonium sulphate concentration provided significant interaction for the RSM model in the isolate AQ5-12. Meanwhile, AQ5-13 showed significance in all five parameters: pH, UCO concentration, temperature, yeast extract, and ammonium sulphate concentration. The degradation efficiency validated via RSM demonstrated better results than the OFAT approach. The model validation has verified no significant difference between the experimental and predicted values. The ability of these two bacterial isolates to degrade UCO is a worthwhile procedure in the bioremediation of hydrocarbon-rich areas.

We report the complete genome sequence of Vibrio parahaemolyticus strain C5A causing an acute hepatopancreatic necrosis disease (AHPND) in Penaeus vannamei sampled from a culture pond in the east of peninsular Malaysia isolated in 2017.

Aims: Leaf blight disease caused by Pantoea spp. reduces rice yields in numerous nations. However, the exact strategy to combat Pantoea spp. has yet to be determined. Bactronophorus thoracites is a promising source of natural antimicrobial agents due to their potential as a substrate to generate peptides with high antimicrobial activity. This study determined the effects of lactic acid fermentation using Lactobacillus casei ATCC334 as a starter culture on antimicrobial activity against rice pathogens, proximate composition, and amino acid profiles from B. thoracites crude extract. Methodology and results: Bactronophorus thoracites was washed and deshelled to collect the flesh and homogenised at 4 °C before freeze-drying. The freeze-dried samples were fermented with L. casei for 4 to 8 days at 37 °C. The antimicrobial activity, MIC and MBC were determined using a spectrometer. The fermented protein was subjected to proximate and amino acid analyses. The antimicrobial activity of fermented B. thoracites protein (FBTP) was significantly (p<0.05) decreased with the increased fermentation days (from 4 to 8 days). The antimicrobial activity was also increased when the glucose concentration increased from 2% to 3%. However, raising the glucose concentration to 4% decreased the antimicrobial activity. The antimicrobial activity was significantly (p<0.05) increased when the substratewater (S/W) ratio increased from 0.84% to 0.96%. The FBTP (4 days, 3% glucose concentration and 0.96% S/W ratio) showed high antimicrobial activity against Pantoea ananatis and P. stewartii. The MIC and MBC values for FBTP were 500 µg/mL and 250 µg/mL against P. ananatis and P. stewartii. The zones of inhibition value for FBTP were 16.0 ± 0.5 mm (1000 µg/mL) and 9.33 ± 0.57 mm (500 µg/mL) for P. ananatis, and 11.7 ± 0.61 mm (1000 µg/mL), 9.33 ± 0.58 mm (500 µg/mL) and 7.17 ± 0.77 mm (250 µg/mL) for P. stewartii. The proximate composition and amino acid profiles of the freeze-dried protein hydroly

Fusarium oxysporum f. sp. cubense tropical race 4 (FocTR4) is a destructive necrotrophic fungal pathogen afflicting global banana production. Infection process involves the activation of programmed cell death (PCD). In this study, seven Musa acuminata vacuolar processing enzyme (MaVPE1–MaVPE7) genes associated with PCD were successfully identified. Phylogenetic analysis and tissue-specific expression categorized these MaVPEs into the seed and vegetative types. FocTR4 infection induced the majority of MaVPE expressions in the susceptible cultivar “Berangan” as compared to the resistant cultivar “Jari Buaya.” Consistently, upon FocTR4 infection, high caspase-1 activity was detected in the susceptible cultivar, while low level of caspase-1 activity was recorded in the resistant cultivar. Furthermore, inhibition of MaVPE activities via caspase-1 inhibitor in the susceptible cultivar reduced tonoplast rupture, decreased lesion formation, and enhanced stress tolerance against FocTR4 infection. Additionally, the Arabidopsis VPE-null mutant exhibited higher tolerance to FocTR4 infection, indicated by reduced sporulation rate, low levels of H2O2 content, and high levels of cell viability. Comparative proteomic profiling analysis revealed increase in the abundance of cysteine proteinase in the inoculated susceptible cultivar, as opposed to cysteine proteinase inhibitors in the resistant cultivar. In conclusion, the increase in vacuolar processing enzyme (VPE)-mediated PCD played a crucial role in modulating susceptibility response during compatible interaction, which facilitated FocTR4 colonization in the host.

The genus Aeromonas has been recognised as an important pathogenic species in aquaculture that causes motile Aeromonas septicaemia (MAS) or less severe, chronic infections. This study compares the pathogenicity of the different Aeromonas spp. that were previously isolated from freshwater fish with signs of MAS. A total of 124 isolates of Aeromonas spp. were initially screened for the ability to grow on M9 agar with myo-inositol as a sole carbon source, which is a discriminatory phenotype for the hypervirulent A. hydrophila (vAh) pathotype. Subsequently, LD50 of six selected Aeromonas spp. were determined by intraperitoneal injection of bacterial suspension containing 103, 105, and 107 CFU/mL of the respective Aeromonas sp. to red hybrid tilapias. The kidneys, livers and spleens of infected moribund fish were examined for histopathological changes. The screening revealed that only A. dhakensis 1P11S3 was able to grow using myo-inositol as a sole carbon source, and no vAh strains were identified. The LD50–240h of A. dhakensis 1P11S3 was 107 CFU/mL, while the non-myo-inositol utilizing A. dhakensis 4PS2 and A. hydrophila 8TK3 was lower at 105 CFU/mL. Similarly, tilapia challenged with the myo-inositol A. dhakensis 1P11S3 showed significantly (p < 0.05) less severe signs, gross and histopathological lesions, and a lower mortality rate than the non-myo-inositol A. dhakensis 4PS2 and A. hydrophila 8TK3. These findings suggested that myo-inositol utilizing A. dhakensis 1P11S3 was not a hypervirulent Aeromonas sp. under current experimental disease challenge conditions, and that diverse Aeromonas spp. are of concern in aquaculture farmed freshwater fish. Therefore, future study is warranted on genomic level to further elucidate the influence of myo-inositol utilizing ability on the pathogenesis of Aeromonas spp., since this ability correlates with hypervirulence in A. hydrophila strains.

The usage of plant growth-promoting (PGP) Streptomyces to improve plant growth is an alternative to existing strategies of chemical fertilizers that commonly caused environmental pollution. The aim of this study was to isolate and characterize PGP Streptomyces from Malaysian rice fields with antagonistic activity against Bacterial Panicle Blight disease in rice caused by Burkholderia glumae. A total of 50 bacterial isolates were recovered from the soil, rhizosphere, and endosphere; 22% showed antagonistic activity against B. glumae. Molecular identification using 16S rRNA amplification and phylogenetic tree analyses revealed that the antagonistic isolates belonged to the genus Streptomyces. Among the antagonistic isolates, Streptomyces sp. TBS5 (26.35 ± 0.14 mm) demonstrated the most antagonistic activity (p < 0.05) against B. glumae. Through API® ZYM analysis, the antagonistic isolates were revealed to have phosphoric hydrolase, ester hydrolase, peptide hydrolase, and glycosidase activities that play a crucial role in plant growth promotion. The antagonistic isolates demonstrated the highest (80%) PGP traits including able to fix nitrogen and solubilize phosphate, as well as produce siderophore and indole-3-acetic acid. Plant growth promotion assay under laboratory and greenhouse conditions were analyzed with the treatment of rice, Oryza sativa, seeds with the antagonistic isolates. Seeds treated with Streptomyces sp. TBS5, JAS2, R2-7, and TKR8 showed improvement in vigor index by more than 100% compared to water-treated control plants under both conditions. Augmentation of root length showed an overall increment of more than 101.5% under laboratory condition and 151.9% under greenhouse condition using Streptomyces sp. TBS5, JAS2, R2-7, and TKR8 treatments. Results suggest that Streptomyces sp. TBS5, JAS2, R2-7, and TKR8 are a good candidate to be developed as both biocontrol agent against B. glumae and PGP agent in rice.