Li Yanlin, Chen Jixiang, Wang Yonggang, Ma Dan, Rui Wenhong
School of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou, China.
Chongqing Key Laboratory of Environmental Materials & Remediation Technologies/College of Chemistry and Environmental Engineering, Chongqing University of Arts and Sciences, Chongqing, China.
PeerJ. 2020 Dec 21;8:e10342. doi: 10.7717/peerj.10342. eCollection 2020.
Numerous bacteria entered the viable but non-culturable state due to the stresses of dry and salt in soils. YeaZ of Gram-negative bacteria is a resuscitation promoting factor (Rpf) homologous protein could resuscitate bacteria of natural environment in VBNC state. To investigate the promoting effect of YeaZ on the isolation of viable but non-culturable (VBNC) bacteria from soil samples in extreme environments, the recombinant YeaZ of was prepared and added to the soil samples from volcanic soil and saline soil in Northwest China. The study has shown that YeaZ can promote the recovery and growth of soil microorganisms, and the number of cultivable bacteria in volcanic and saline soil has increased from 0.17 × 10 and 2.03 × 10 cfu⋅ml to 1.00 × 10 and 5.55 × 10 cfu⋅ml, respectively. The 16S rDNA gene sequencing and phylogenetic analysis showed that YeaZ played an essential role in the increase of composition and diversity of bacteria. A total of 13 bacterial strains were isolated from the volcanic soil samples, which belong to phyla Actinobacteria, Firmicutes and Gamma-proteobacteria. Four species, including , , and were found in the control group, while , , , , and were isolated from the treatment groups (addition of YeaZ). Twenty-one strains were isolated from the saline soil samples, including eight species from the control group and thirteen species from the treatment groups, among which nine species were only found, including , , , , , , , and . The results suggest that addition of YeaZ to soil samples can promote the recovery of VBNC. This method has the implications for the discovery of VBNC bacteria that have potential environmental functions.
由于土壤中干旱和盐分的胁迫，大量细菌进入了活的但不可培养状态。革兰氏阴性菌的YeaZ是一种复苏促进因子（Rpf）同源蛋白，可复苏处于活的但不可培养（VBNC）状态的自然环境中的细菌。为了研究YeaZ对从极端环境土壤样品中分离活的但不可培养（VBNC）细菌的促进作用，制备了重组YeaZ并将其添加到中国西北火山土和盐土的土壤样品中。研究表明，YeaZ可以促进土壤微生物的恢复和生长，火山土和盐土中可培养细菌的数量分别从0.17×10和2.03×10 cfu·ml增加到1.00×10和5.55×10 cfu·ml。16S rDNA基因测序和系统发育分析表明，YeaZ在细菌组成和多样性的增加中起重要作用。从火山土样品中总共分离出13株细菌，它们属于放线菌门、厚壁菌门和γ-变形菌门。对照组中发现了4个物种，包括 、 、 和 ，而处理组（添加YeaZ）中分离出了 、 、 、 、 和 。从盐土样品中分离出21株菌株，其中对照组有8个物种，处理组有13个物种，其中仅发现9个物种，包括 、 、 、 、 、 、 、 和 。结果表明，向土壤样品中添加YeaZ可以促进VBNC的复苏。该方法对发现具有潜在环境功能的VBNC细菌具有启示意义。
