Transcriptomic Analysis of Histamine Degradation by Bacillus subtilis under Salt Stress
In order to explore the mechanism of histamine degradation of Bacillus subtilis under salt stress,B.subtilis JZXJ-7 was used as the experimental strain,and cultured in liquid culture environment with 170 mmol/L and 340 mmol/L NaCl for 48 h.Histamine degradation rate and colony growth were measured,and transcripome high-throughput sequenc-ing was performed on the degraded strain.The differential gene expression and related metabolic pathways of strains in different NaCl addition groups were detected during reducing amine process.Results showed that the degradation rate of histamine after adding 170 mmol/L and 340 mmol/L NaCl was significantly higher than control group(P＜0.05),which were 62.93％ and 84.87％ ,respectively.The total number of colonies was significantly increased(P＜0.05),which were 4.13 ×105 CFU/mL and 4.53×105 CFU/mL,respectively.Transcriptome analysis showed that differentially expressed genes were significantly up-regulated in the salt stress group,and the main up-regulated functional genes were serine acetyl-transferase,major facilitator superfamily(MFS)transporter and type Ⅰ secretory system penetrase.The significantly down-regulated functional genes were histidine kinase,type Ⅱ 3-dehydroate dehydrase and shikimic dehydrogenase.GO func-tional enrichment analysis mainly involved metabolic process,cell transformation,cell anatomical entity,structural molec-ular activity,catalytic activity and binding ability.The metabolic pathway of KEGG involved pyruvate metabolism,pen-tose phosphate pathway,two-component system and arginine biosynthesis.Results revealed that salt stress was more con-ducive to B.subtilis to promote gene expression,activate metabolic pathways,and increase histamine degradation rate.This study provided an important theoretical basis and reference for the subsequent strains to be applied in food fermen-tation industry to further degrade biogenic amines efficiently.
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维普
