Statistical Optimization of Alkali Pretreatment to Improve Sugars Recovery from Spent Coffee Grounds and Utilization in Lactic Acid Fermentation
Statistical Optimization of Alkali Pretreatment to Improve Sugars Recovery from Spent Coffee Grounds and Utilization in Lactic Acid Fermentation
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DOI：
10.3390/pr9030494
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发表时间：
2021-03-01
期刊：
影响因子：
3.5
通讯作者：
Yoo, Hah Young
中科院分区：
文献类型：
--
作者：
Lee, Kang Hyun;Jang, Ye Won;Yoo, Hah Young
利用碳中性生物质作为资源的生物炼制作为气候变化的现代社会的重要替代方案而备受关注。本研究以废咖啡渣（SCGs）为原料进行乳酸发酵。为了提高糖的转化率，采用响应面法（RSM）对碱预处理进行了优化。确定了SCGs碱预处理的最佳条件：75℃，3%氢氧化钾（KOH）， 2.8 h。确定了预处理后SCGs酶解的最佳条件：以每g生物量30单位纤维素酶、15单位纤维素酶和50单位甘露聚糖酶的酶配合物为碳源，以SCG水解物为碳源进行乳酸培养，短乳杆菌ATCC 8287和副abuchneri L. ATCC 49374的乳酸转化率分别为40.1%和55.8%。最后，通过碱预处理和酶解优化，拟副abuchneri ATCC 49374在1000 g SCGs的基础上，乳酸产量最大可达101.2 g。
Biorefinery, which utilizes carbon-neutral biomass as a resource, is attracting attention as a significant alternative in a modern society confronted with climate change. In this study, spent coffee grounds (SCGs) were used as the feedstock for lactic acid fermentation. In order to improve sugar conversion, alkali pretreatment was optimized by a statistical method, namely response surface methodology (RSM). The optimum conditions for the alkali pretreatment of SCGs were determined as follows: 75 degrees C, 3% potassium hydroxide (KOH) and a time of 2.8 h. The optimum conditions for enzymatic hydrolysis of pretreated SCGs were determined as follows: enzyme complex loading of 30-unit cellulase, 15-unit cellobiase and 50-unit mannanase per g biomass and a reaction time of 96 h. SCG hydrolysates were used as the carbon source for Lactobacillus cultivation, and the conversions of lactic acid by L. brevis ATCC 8287 and L. parabuchneri ATCC 49374 were 40.1% and 55.8%, respectively. Finally, the maximum lactic acid production by L. parabuchneri ATCC 49374 was estimated to be 101.2 g based on 1000 g of SCGs through the optimization of alkali pretreatment and enzymatic hydrolysis.