Lignocellulosic wastes are abundant and considered as the important feedstock. It is a value-added product by using microorganisms. Yet little is known regarding usage of lignocellulosic biomass by anoxygenic photosynthetic bacteria although they provide various applications and their biomass are rich in essential nutrients. This limits applications between lignocellulosic wastes and phototrophic bacteria. We examined growth and valuable products of photosynthetic bacterium Rhodopseudomonas faecalis PA2 cultivated in different lignocellulosic waste suspension under light condition. Suspension of rice straw, bagasse, coconut meal, soybean meal, corncob, fiber of palmyra palm peel, and spent coffee ground were prepared by filtration or boiling to be used as sole substrates without additional nutrients. Here we show that the selected strain could grow in the lignocellulosic waste suspension without heat pretreatment. Soybean meal showed the highest biomass, carbohydrate, lipid, carotenoid and bacteriochlorophyll productivities of 0.71 g/L/day, 350, 9.61, 33.11 and 212.54 mg/L/day, respectively, whereas coconut meal was the best substrate for protein productivity (138.61 mg/L/day). Rice straw and fiber of palmyra palm peel seem to be interesting and utilization of fiber of palmyra palm peel in microbial cultivation is reported for the first time. Our results demonstrate that lignocellulosic material suspension can be used as the promising substrates to produce valuable biomass from anoxygenic photosynthetic bacteria without pretreatment and secondary solid waste. We anticipate our investigation to be a starting point for further simultaneous value-added product production by anoxygenic photosynthetic bacteria as well as lignocellulosic waste utilization.

Graphic Abstract

中文翻译：

---

木质纤维素废料的增值和无氧光合细菌的营养回收

木质纤维素废料丰富，被认为是重要的原料。它是利用微生物的增值产品。关于产氧光合细菌对木质纤维素生物质的利用知之甚少，尽管它们提供了多种应用，并且其生物质富含必需的营养素。这限制了木质纤维素废料和光养细菌之间的应用。我们检查了光合细菌粪红假单胞菌的生长和有价值的产品在光照条件下在不同的木质纤维素废液悬浮液中培养的PA2。通过过滤或煮沸制备稻草，蔗渣，椰子粉，豆粕，玉米芯，棕榈叶果皮纤维和用过的咖啡渣的悬浮液，将其用作唯一的底物，而无需额外的营养。在这里，我们表明所选的菌株可以在无需热处理的情况下在木质纤维素废液悬浮液中生长。大豆粉的最高生物量，碳水化合物，脂质，类胡萝卜素和细菌叶绿素的生产率分别为0.71 g / L /天，350、9.61、33.11和212.54 mg / L /天，而椰子粉是蛋白质生产力的最佳底物（138.61毫克/升/天）。稻草和扇叶树棕榈纤维似乎很有趣，首次报道了扇叶树棕榈纤维在微生物栽培中的利用。我们的结果表明，木质纤维素材料悬浮液可以用作有前途的底物，从无氧光合细菌产生有价值的生物质，而无需预处理和二次固体废物。我们希望我们的调查将成为进一步通过产氧光合细菌同时生产增值产品以及利用木质纤维素废料的起点。

图形摘要