Chinn Mari S, Nokes Sue E, Strobel Herbert J
Department of Biosystems and Agricultural Engineering, University of Kentucky, 215 C. E. Barnhart Building, Lexington, Kentucky 40546-0276, USA.
Biotechnol Prog. 2006 Jan-Feb;22(1):53-9. doi: 10.1021/bp050163x.
Interest in solid substrate cultivation (SSC) techniques is gaining for biochemical production from renewable resources; however, heat and mass transfer problems may limit application of this technique. The use of anaerobic thermophiles in SSC offers a unique solution to overcoming these challenges. The production potential of nine thermophilic anaerobic bacteria was examined on corn stover, sugar cane bagasse, paper pulp sludge, and wheat bran in submerged liquid cultivation (SmC) and SSC. Production of acetate, ethanol, and lactate was measured over a 10 day period, and total product concentrations were used to compare the performance of different organism-substrate combinations using the two cultivation methods. Overall microbial activity in SmC and SSC was dependent on the organism and growth substrate. Clostridium thermocellum strains JW20, LQRI, and 27405 performed significantly better in SSC when grown on sugar cane bagasse and paper pulp sludge, producing at least 70 and 170 mM of total products, respectively. Growth of C. thermocellum strains in SSC on paper pulp sludge proved to be most favorable, generating at least twice the concentration of total products produced in SmC (p-value < 0.05). Clostridium thermolacticum TC21 demonstrated growth on all substrates producing 30-80 and 60-116 mM of total product in SmC and SSC, respectively. Bacterial species with optimal growth temperatures of 70 degrees C grew best on wheat bran in SmC, producing total product concentrations of 45-75 mM. For some of the organism-substrate combinations total end product concentrations in SSC exceeded those in SmC, indicating that SSC may be a promising alternative for microbial activity and value-added biochemical production.
人们对利用可再生资源进行生化生产的固体基质培养（SSC）技术的兴趣日益浓厚；然而，传热传质问题可能会限制该技术的应用。在SSC中使用嗜热厌氧菌为克服这些挑战提供了独特的解决方案。研究了9种嗜热厌氧菌在玉米秸秆、甘蔗渣、纸浆污泥和麦麸上进行深层液体培养（SmC）和SSC时的生产潜力。在10天的时间内测量了乙酸、乙醇和乳酸的产量，并使用总产物浓度来比较两种培养方法下不同微生物-底物组合的性能。SmC和SSC中的总体微生物活性取决于微生物和生长底物。嗜热栖热菌菌株JW20、LQRI和27405在以甘蔗渣和纸浆污泥为生长底物的SSC中表现明显更好，分别产生至少70 mM和170 mM的总产物。嗜热栖热菌菌株在纸浆污泥上进行SSC培养时生长最为有利，产生的总产物浓度至少是SmC中产生浓度的两倍（p值<0.05）。嗜热乳酸梭菌TC21在所有底物上均能生长，在SmC和SSC中分别产生30 - 80 mM和60 - 116 mM的总产物。最佳生长温度为70摄氏度的细菌物种在SmC中以麦麸为底物时生长最佳，产生的总产物浓度为45 - 75 mM。对于一些微生物-底物组合，SSC中的总终产物浓度超过了SmC中的浓度，这表明SSC可能是微生物活性和增值生化生产的一种有前景的替代方法。
