Synergistic growth in bacteria depends on substrate complexity.
Synergistic growth in bacteria depends on substrate complexity.
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DOI：
10.1007/s12275-016-5461-9
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发表时间：
2016-01
期刊：
影响因子：
--
通讯作者：
Wang SY
中科院分区：
文献类型：
--
作者：
Deng YJ;Wang SY
细菌之间的积极和消极相互作用都发生在环境中。我们推测，底物的复杂性影响细菌在柠檬酸盐底物存在下更大合作的相互作用方式。我们从盐沼碎屑中分离出木质纤维素分解菌，并比较了纯培养物与三种混合培养物在木质纤维素和葡萄糖培养基中的生长、代谢活性和产酶情况。在含有羧甲基纤维素、木聚糖和木质素的木质纤维素培养基中存在协同生长，而在葡萄糖培养基中不存在。细菌协同作用促进协同混合培养物中的代谢活性，但不促进最大生长速率（μ）。细菌协同作用也促进了β-1，4-葡萄糖苷酶的产生，但对纤维二糖水解酶和β-1，4-木糖苷酶的产生没有促进作用。我们的研究结果表明，底物的化学复杂性影响细菌相互作用的方式。虽然复杂的底物如木质纤维素促进积极的相互作用和协同生长，但不稳定的底物如葡萄糖促进消极的相互作用和竞争。土著细菌之间的协同作用，建议是重要的，在促进环境中的木质纤维素降解。
Both positive and negative interactions among bacteria take place in the environment. We hypothesize that the complexity of the substrate affects the way bacteria interact with greater cooperation in the presence of recalcitrant substrate. We isolated lignocellulolytic bacteria from salt marsh detritus and compared the growth, metabolic activity and enzyme production of pure cultures to those of three-species mixed cultures in lignocellulose and glucose media. Synergistic growth was common in lignocellulose medium containing carboxyl methyl cellulose, xylan and lignin but absent in glucose medium. Bacterial synergism promoted metabolic activity in synergistic mixed cultures but not the maximal growth rate (μ). Bacterial synergism also promoted the production of β-1,4-glucosidase but not the production of cellobiohydrolase or β-1,4-xylosidase. Our results suggest that the chemical complexity of the substrate affects the way bacteria interact. While a complex substrate such as lignocellulose promotes positive interactions and synergistic growth, a labile substrate such as glucose promotes negative interactions and competition. Synergistic interactions among indigenous bacteria are suggested to be important in promoting lignocellulose degradation in the environment.