Purpose

To isolate, identify and characterize an anaerobic strain from in natura CPW, in relation to the consumption of different carbon sources, growth kinetics and H₂ production after bioaugmentation.

Methods

Several substrates were evaluated (glucose, fructose, sucrose, xylose, starch, cellobiose, cellulose and lactose), and its optimal concentration was evaluated by Experimental Design method, besides the application of the isolated strain in citrus peel waste (CPW).

Results

A facultative anaerobic strain, similar (99%) to Enterococcus casseliflavus, was isolated from in natura citrus pulp and bagasse. Xylose was the monomer from which there was greater H₂ production (10.3 mmol L⁻¹). For 0.5 to 6.5 g_xylose L⁻¹, 3.0 to 12.9 mmol H₂ L⁻¹ was obtained, respectively. Generation time (Tg) of 0.35 h and specific growth (µ) of 1.98 h⁻¹ for pH 7.0, 37 °C and 2 g _glucose L⁻¹ was obtained for E. casseliflavus. In bioaugmentation assays (CPW + E. casseliflavus), highest maximum H₂ production potential (P = 13.9 mmol L⁻¹), maximum H₂ production rate (Rm = 1.09 mmol h⁻¹) and time to start the H₂ production (λ = 2.12 h⁻¹) was observed when compared to glucose (P = 9.1 mmol L⁻¹; Rm = 1.99 mmol h⁻¹; λ = 4.08 h⁻¹).

Conclusion

From glucose, there was prevalence of butyric acid pathway (759 mg L⁻¹) in relation to acetic acid (303 mg L⁻¹). From CPW, there was higher production of acetic acid (878 mg L⁻¹) in relation to butyric (147 mg L⁻¹). The application of E. casseliflavus by bioaugmentation is an alternative for biodigestion of complex substrates, such as CPW, to obtain products of biotechnological interest.

Graphic Abstract

目的

要分离，鉴定和表征自然界CPW中的厌氧菌株，与生物强化后不同碳源的消耗，生长动力学和H ₂产生有关。

方法

评价了几种底物（葡萄糖，果糖，蔗糖，木糖，淀粉，纤维二糖，纤维素和乳糖），除了将分离的菌株应用于柑桔皮废料（CPW）中之外，还通过实验设计方法评估了其最佳浓度。

结果

从纳塔尔柑橘果肉和蔗渣中分离出一种兼性厌氧菌株，与卡氏肠球菌相似（99％）。木糖是产生更多的H ₂（10.3 mmol L ^-1）的单体。对于0.5至6.5g的_木糖 L ^-1，分别获得3.0至12.9mmol的H ₂  L ^-1。生成时间（Tg的的1.98ħ0.35小时，比生长率（μ））^-1为pH为7.0，37℃和2g_葡萄糖 大号^-1为获得E. casseliflavus。在生物增强测定中（CPW +  casseliflavus），最高的最大H ₂产生潜能（P  = 13.9 mmol L ^-1），最大的H ₂产生速率（Rm  = 1.09 mmol h ^-1）和开始产生H _2的时间（λ= 2.12 h ^-1）被观察到与葡萄糖比较时（P  ＝ 9.1mmol L ^-1；Rm  ＝ 1.99mmol h ^-1；λ＝ 4.08h ^-1）。

结论

从葡萄糖中，丁酸途径（759 mg L ^-1）相对于乙酸（303 mg L ^-1）的流行。从CPW，有较高的生产乙酸（878毫克的L的^-1相）到丁酸（147毫克的L ^-1）。通过生物增强作用来应用卡塞弗拉维斯菌是对复杂底物（例如CPW）进行生物消化以获取具有生物技术意义的产品的另一种方法。

图形摘要