Phototrophic Lactate Utilization by Rhodopseudomonas palustris Is Stimulated by Coutilization with Additional Substrates
Phototrophic Lactate Utilization by Rhodopseudomonas palustris Is Stimulated by Coutilization with Additional Substrates
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DOI：
10.1128/aem.00048-19
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发表时间：
2019-06-01
影响因子：
4.4
通讯作者：
LaSarre, Breah
中科院分区：
文献类型：
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作者：
Govindaraju, Alekhya;McKinlay, James B.;LaSarre, Breah
光合紫色非硫细菌沼泽红球藻以其代谢多样性而闻名，并在各种工业和环境应用中受到关注。尽管对R.不同条件下沼泽化R.沼泽生长和碳利用与碳基质的混合物仍然在很大程度上未知。R.沼生菌容易利用大多数短链有机酸，但不能容易地利用乳酸盐作为唯一的碳源。本文研究了混合基质利用对红球藻光合乳酸消耗的影响。沼泽我们发现，乳酸盐与各种其他有机酸和甘油在时间范围内同时被利用，这对于R.沼泽生长的乳酸单独。因此，乳酸的利用R。palustris通过其与额外底物的利用而加速。另外，使用不含乳酸的碳对的实验揭示了乙酸介导的对R.沼泽这种抑制作用对乙酸-甘油对是特异性的，如R。palustris同时利用乙酸或甘油时，与琥珀酸或乳酸配对。总体而言，我们的研究结果表明：（i）R。palustris通常采用同时混合底物利用，（ii）混合底物利用扩大了该物种易于利用的有机酸的光谱，和（iii）R. palustris有能力发挥碳代谢产物控制在一个具体的substrate-specific mathematics.IMPORTANCE细菌的碳源利用率经常评估使用文化提供单一的碳源。然而，细菌对碳混合物的利用（即，混合底物利用）具有基础和实际重要性;它是细菌生理学和生态学的核心，并且它影响细菌作为生物技术的效用。在这里，我们调查了混合底物利用模式生物沼泽红球藻。利用有机酸和甘油的混合物，我们表明，R。当以混合物的形式提供底物时，沼泽地植物表现出扩大的可用碳底物范围。具体来说，利用能够迅速消耗乳酸盐，乳酸盐是一种不容易被R利用的底物。沼泽此外，我们还发现R. palustris依次利用乙酸盐和甘油，这表明该物种具有以优先顺序利用某些底物的能力。这些结果提供了对R. palustris生理学，这将有助于使用R。用于工业和商业应用的沼泽。
The phototrophic purple nonsulfur bacterium Rhodopseudomonas palustris is known for its metabolic versatility and is of interest for various industrial and environmental applications. Despite decades of research on R. palustris growth under diverse conditions, patterns of R. palustris growth and carbon utilization with mixtures of carbon substrates remain largely unknown. R. palustris readily utilizes most short-chain organic acids but cannot readily use lactate as a sole carbon source. Here we investigated the influence of mixed-substrate utilization on phototrophic lactate consumption by R. palustris. We found that lactate was simultaneously utilized with a variety of other organic acids and glycerol in time frames that were insufficient for R. palustris growth on lactate alone. Thus, lactate utilization by R. palustris was expedited by its coutilization with additional substrates. Separately, experiments using carbon pairs that did not contain lactate revealed acetate-mediated inhibition of glycerol utilization in R. palustris. This inhibition was specific to the acetate-glycerol pair, as R. palustris simultaneously utilized acetate or glycerol when either was paired with succinate or lactate. Overall, our results demonstrate that (i) R. palustris commonly employs simultaneous mixed-substrate utilization, (ii) mixed-substrate utilization expands the spectrum of readily utilized organic acids in this species, and (iii) R. palustris has the capacity to exert carbon catabolite control in a substrate-specific manner.IMPORTANCE Bacterial carbon source utilization is frequently assessed using cultures provided single carbon sources. However, the utilization of carbon mixtures by bacteria (i.e., mixed-substrate utilization) is of both fundamental and practical importance; it is central to bacterial physiology and ecology, and it influences the utility of bacteria as biotechnology. Here we investigated mixed-substrate utilization by the model organism Rhodopseudomonas palustris. Using mixtures of organic acids and glycerol, we show that R. palustris exhibits an expanded range of usable carbon substrates when provided substrates in mixtures. Specifically, coutilization enabled the prompt consumption of lactate, a substrate that is otherwise not readily used by R. palustris. Additionally, we found that R. palustris utilizes acetate and glycerol sequentially, revealing that this species has the capacity to use some substrates in a preferential order. These results provide insights into R. palustris physiology that will aid the use of R. palustris for industrial and commercial applications.