BACKGROUND Enterobacter sp. AA26 was recently isolated from the midgut of Ceratitis capitata (Wiedemann) and it was shown to have positive effects in rearing efficiency when used as larval probiotics. In this study, biomass production was carried out in bench-scale bioreactors to elucidate the biokinetic properties of Enterobacter sp. AA26 and its nutritional value. RESULTS Strain AA26 is a psychrotolerant, halotolerant, facultatively anaerobic bacterium with broad pH range for growth (pH 4 to 10.2), which possessed the typical biochemical profile of Enterobacter spp. The specific oxygen uptake rate (SOUR) was calculated as 63.2 ± 1.26 and 121 ± 1.73 mg O2 g- 1 VSS h- 1, with the yield coefficients in acetate and glucose being equal to 0.62 ± 0.03 and 0.67 ± 0.003 g biomass produced/g substrate consumed, respectively. The maximum specific growth rate (μmax) of strain AA26 grown in fill-and-draw bioreactors at 20 °C and 35 °C was 0.035 and 0.069 h- 1, respectively. Strain AA26 grew effectively in agro-industrial wastewaters, i.e. cheese whey wastewater (CWW), as alternative substrate for replacing yeast-based media. Biomass of strain AA26 could provide all the essential amino acids and vitamins for the artificial rearing of C. capitata. Greater intracellular α- and β-glucosidase activities were observed during growth of strain AA26 in CWW than in yeast-based substrate, although the opposite pattern was observed for the respective extracellular activities (p < 0.01). Low protease activity was exhibited in cells grown in yeast-based medium, while no lipase activities were detected. CONCLUSIONS The ability of strain AA26 to grow in agro-industrial wastes and to provide all the essential nutrients can minimize the cost of commercial media used for mass rearing and large scale sterile insect technique applications.

中文翻译：

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墨蝇肠道共生肠杆菌属细菌的生化和营养表征。AA26用作无菌昆虫技术应用中的益生菌。

背景肠杆菌属。AA26是最近从人参猪中肠（Wiedemann）的中肠中分离出来的，当用作幼虫益生菌时，它对提高饲养效率具有积极作用。在这项研究中，生物量生产在台式规模的生物反应器中进行，以阐明肠杆菌的生物动力学特性。AA26及其营养价值。结果AA26菌株是一种耐精神性，耐盐性，兼性厌氧性细菌，具有广泛的pH生长范围（pH 4至10.2），具有典型的肠杆菌属生化特征。计算的单位氧气吸收率（SOUR）为63.2±1.26和121±1.73 mg O2 g-1 VSS h-1，乙酸盐和葡萄糖的产量系数等于0.62±0.03和0.67±0.003 g产生的生物量/ g分别消耗的底物。在填充和拉伸生物反应器中在20°C和35°C下生长的AA26菌株的最大比生长率（μmax）分别为0.035和0.069 h-1。AA26菌株在农业工业废水（即奶酪乳清废水（CWW））中有效生长，作为替代基于酵母的培养基的替代基质。菌株A26的生物质可以为人工养殖角衣梭菌提供所有必需的氨基酸和维生素。尽管在CWW中AA26菌株的生长过程中观察到的细胞内α-和β-葡萄糖苷酶活性高于酵母基基质，但在各自的细胞外活性中却观察到相反的模式（p <0.01）。在基于酵母的培养基中生长的细胞中显示出低蛋白酶活性，而未检测到脂肪酶活性。