Studies on screening and biologically characterizing bacteriostatic halophilic bacteria from Qinghai salt lakes
YANG Haishan
ZOU Zhongyang
ZHANG Xin
ZHAO Lingli
ZHANG Xiang
ZHANG Haixia
ZHU Derui
LI Yongzhen
Abstract：In this study,32 strains of halophilic bacteria from Xiaoqaidan Salt Lake,Qinghai Lake and Keke Salt Lake were fermented with their intracellular products extracted.The bacterial strains per-forming antibacterial activity were screened with filter paper method(K-B method).Six strains of hal-ophilic bacteria including K-20,X-32,Q-10,Q-19 and Q-31,were found to inhibit Bacillus subtilis,E.coli and Staphylococcus aureus and Enterococcus faecalis while B.zhangzhou showed an antibacte-rial activity.The active strains were characterized biologically under different culturing conditions.The results showed that 6 active strains are all Gram negative and shape as a long rod or arcuate.The opti-mal growth salt concentration(NaCl)of the 6 strains ranged from 0.5 to 2.5 mol/L,belonging to the moderate halophilic.Of them,Q-31 was halophilic with the optimal growth acidity varied between pH6.0 and pH8.0,and the optimal growth temperature 37 ℃.Biochemical identification revealed that these strains can grow using yeast extract,casein,tryptone and other nitrogen sources.K-20,X-20,X-32 and Q-31 can liquefy gelatin(GEL)while X-20,X-32,Q-10 and Q-31 produce urease(URE)and reduce nitrate.The phylogenetic analysis of 16S rRNA gene sequence showed that the active strains be-long to Halomonas,Bacillus,Vibrio and Sphingomonas,respectively.
Keywords：halophilic bacteriumscreeningbacteriostatic effectbiological characteristicsphylogeny
Publication Date：2025-12-30
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：11( 108-118 )