Hiraishi Akira, Nagao Nobuyoshi, Yonekawa Chinatsu, Umekage So, Kikuchi Yo, Eki Toshihiko, Hirose Yuu
Department of Environmental and Life Sciences, Toyohashi University of Technology, Toyohashi 441-8580, Japan.
Department of Applied Chemistry and Life Science, Toyohashi University of Technology, Toyohashi 441-8580, Japan.
Microorganisms. 2020 Jan 22;8(2):150. doi: 10.3390/microorganisms8020150.
The biodiversity of phototrophic purple nonsulfur bacteria (PNSB) in comparison with purple sulfur bacteria (PSB) in colored blooms and microbial mats that developed in coastal mudflats and pools and wastewater ditches was investigated. For this, a combination of photopigment and quinone profiling, gene-targeted quantitative PCR, and gene clone library analysis was used in addition to conventional microscopic and cultivation methods. Red and pink blooms in the coastal environments contained PSB as the major populations, and smaller but significant densities of PNSB, with members of predominating. On the other hand, red-pink blooms and mats in the wastewater ditches exclusively yielded PNSB, with , , and/or as the major constituents. The important environmental factors affecting PNSB populations were organic matter and sulfide concentrations and oxidation‒reduction potential (ORP). Namely, light-exposed, sulfide-deficient water bodies with high-strength organic matter and in a limited range of ORP provide favorable conditions for the massive growth of PNSB over co-existing PSB. We also report high-quality genome sequences of sp. strain MB263, previously isolated from a pink mudflat, and DSM 1374, which would enhance our understanding of how PNSB respond to various environmental factors in the natural ecosystem.
研究了在沿海泥滩、池塘和废水沟渠中形成的有色水华和微生物垫中，光合紫色非硫细菌（PNSB）与紫色硫细菌（PSB）相比的生物多样性。为此，除了传统的显微镜和培养方法外，还使用了光合色素和醌谱分析、基因靶向定量PCR以及基因克隆文库分析相结合的方法。沿海环境中的红色和粉色水华以PSB为主要种群，PNSB的密度较小但显著，其中 成员占主导地位。另一方面，废水沟渠中的红粉色水华和微生物垫仅产生PNSB，以 、 和/或 为主要成分。影响PNSB种群的重要环境因素是有机物、硫化物浓度和氧化还原电位（ORP）。也就是说，暴露于光照、缺乏硫化物、含有高强度有机物且ORP范围有限的水体为PNSB相对于共存的PSB大量生长提供了有利条件。我们还报告了先前从粉色泥滩分离的 菌株MB263和DSM 1374的高质量基因组序列，这将增强我们对PNSB如何在自然生态系统中响应各种环境因素的理解。
