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Antibacterial characterization of Bacillus velezensis LG37 and mining of genes related to biosynthesis of antibacterial substances
Get PDFBacillus velezensis LG37 secretes various antibacterial substances and inhibits the growth of other bacteria. Here, we analyzed the antibacterial characteristics and the screening and verification of genes related to the synthesis of the antibacterial substance of LG37 by antibacterial activities experiment, Local BLAST+, and RT-PCR. LG37 was isolated from aquaculture water and preserved in our laboratory. The phylogenetic tree was used to analyze the genetic relationship between LG37 and the bacteriostatic test indicator strain. LG37 had a more substantial inhibitory effect on closely related strains, while the inhibitory effect on the more distantly related strains was weak. Combined with the results of genome sequencing, the ribosomal peptide (RP) bacteriocin gene and non-ribosomal peptide synthetase (NRPSs) related gene clusters were screened and analyzed. A total of six gene-coding RP bacteriocins and two genes coding surfactins and fengycin A NRPSs gene cluster were screened. Local BLAST+ analysis revealed a total of 11 NRPSs gene clusters. The active expression of the NRPSs and RP encoding genes was further validated by RT-PCR. The findings revealed various genes and gene clusters encoding RP bacteriocins and NRPSs in B. velezensis LG37. The bacterium is potentially valuable in diverse applications in aquaculture
Transcriptome profiling of Penaeus vannamei hepatopancreas infected with WSSV following feeding diet containing ulvan
Get PDFThe present study aimed to elucidate the mechanism of protection provided by dietary ulvan as observed in previous studies. Thirty shrimps (3.35 ± 0.08 g average body weight) were stocked in six polyethylene tanks (5 shrimps tank-1, treatments were in three replicate/tank) and were fed either a diet containing no ulvan (control) or containing ulvan at 1 g kg diet-1 for 35 days at 10% body weight twice daily. At the termination of the feeding, the shrimps were subjected to a white spot syndrome virus (WSSV) challenge test via intramuscular injection of the viral inoculum. Shrimps were sacrificed after 24 h of exposure, and the hepatopancreas was excised for total RNA extraction for transcriptome profiling. Biological validation of the RNA-seq results was also performed for 10 immune-related genes (6 up- and 4 down-regulated genes). A comparison of the ulvan group with the control group revealed that 69 differentially expressed genes (DEGs) were significantly up-regulated, whereas 640 were significantly down-regulated. 184 DEGs between the control and ulvan-treated groups were classified into six KEGG categories of Metabolism (145 DEGs), Organismal systems (16), Human disease (4), Genetic Information Processing (10), Cellular Processes (2), and Environmental Information Processing (7). The 145 DEGs under Metabolism were distributed to Level 2 subcategories as carbohydrate metabolism (59 DEGs), global and overview maps (44), energy metabolism (27), and amino acid metabolism (15). All candidate immune-related genes (67) were down-regulated except for 5 genes. The validation experiment showed proportionality of gene expressions of the qPCR and of those in the assembled transcriptome, justifying the acceptability of the RNA-seq results. In conclusion, data from the present study provided mechanisms for protecting the white shrimp by dietary ulvan against WSSV infection
The evaluation of ammonia tolerance in introduced and local Pacific white shrimp, Litopenaeus vannamei, populations in China
Get PDFThe white shrimp, Litopenaeus vannamei, is one of the most valuable commodities in the global seafood trade. Affected by high-density farming environments, ammonia accumulates in shrimp cultures and has a strong toxic effect, resulting in poor shrimp survival and poor immune function and metabolism. We selected six different populations of L. vannamei from Xing Hai No.1 (A and B), CHAI, Sy Aqua, PRIMO, and a second-generation Sy Aqua-PRIMO hybrid population (SP). The shrimps (3.24 ± 0.71 cm body length) were exposed to ammonia (24 h, 48 h), followed by recovery (R48 h, R96 h) to assess the tolerance of different populations. The survival rate (SR), immune-related enzymes (superoxide dismutase SOD, catalase CAT, and Glutathione peroxidase GSH-PX), Malondialdehyde (MDA), and metabolism (glutamate dehydrogenase GDH, glutamine synthetase GS, and aspartic acid transaminase GOT) and were measured at different populations under acute ammonia stress. Multiple comparisons of the ammonia resistance index from six populations showed that the expression of these indicators varied among the populations. The degree of lipid peroxidation in the Sy Aqua and PRIMO was significantly higher than in the other populations (P < 0.05), and the ammonia metabolism index was poor. The GDH and GOT genes for the Xing Hai No.1 (A) were higher than for the other populations. Mortality and physiological indicators recovered to varying degrees for all experimental populations following 96 h of ammonia relief, whereas the Sy Aqua and PRIMO showed a noticeable lag. These results indicated that the immunity and metabolic capacity of Xing Hai No.1 (A) might be higher than those of Sy Aqua and PRIMO. These data could have value in developing future scientific breeding schemes and in the sustainability of shrimp farming
Kahele, Case introduce legislation to expand and protect U.S. cacao and floriculture industries
No full textKahele: Department of Interior takes steps to confront intergenerational trauma by historical federal Indian boarding schools
No full textVideo message for the ‘Ōlelo Community Media 19th Annual Youth Xchange student video competition awards
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