Production of lactic acid from paper sludge using acid-tolerant, thermophilic Bacillus coagulan strains
Production of lactic acid from paper sludge using acid-tolerant, thermophilic Bacillus coagulan strains
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DOI：
10.1016/j.biortech.2009.01.080
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发表时间：
2009-12-01
影响因子：
11.4
通讯作者：
Fan, Zhiliang
中科院分区：
文献类型：
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作者：
Budhavaram, Naresh K.;Fan, Zhiliang
利用嗜热凝结芽孢杆菌36D1和P4-102B对造纸废渣生产乳酸进行了研究。由于CaCO3在造纸污泥中的缓冲作用，两株菌均可在不进行任何pH控制的情况下获得80%以上的乳酸产量和87%以上的纤维素转化率。在富营养液中加入CaCO3作为缓冲剂，提高了乳酸产量，但对纤维素转化率影响不大；添加CaCO3对纤维素转化率和乳酸产量影响不大。降低发酵温度会降低乳酸产量，但会提高纤维素转化率。以100g/L当量纸浆为基质，不加pH控制，在血清瓶中半连续同步糖化共发酵1000h，在富营养化条件下，菌株36D1和P4-102B的平均稳态乳酸浓度分别为92g/L和91.7g/L，乳酸得率分别为77%和78%。采用半连续式厌氧发酵，36D1和P4-102B菌株的平均乳酸浓度分别为77.5g/L和77.0g/L，乳酸产率分别为72%和75%。在富营养化和贫化培养条件下，两株菌的稳态生产力分别为0.96g/L/h和0.82g/L/h。研究结果表明，凝结芽孢杆菌36D1和P4-102B菌株是一种很有前途的超临界流体转化造纸废渣生产乳酸的菌株。(C)2009爱思唯尔有限公司。保留所有权利。
Production of lactic acid from paper sludge was studied using thermophilic Bacillus coagulan strains 36D1 and P4-102B. More than 80% of lactic acid yield and more than 87% of cellulose conversion were achieved using both strains without any pH control due to the buffering effect Of CaCO3 in paper sludge. The addition Of CaCO3 as the buffering reagent in rich medium increased lactic acid yield but had little effect on cellulose conversion; when lean medium was utilized. the addition of CaCO3 had little effect on either cellulose conversion or lactic acid yield. Lowering the fermentation temperature lowered lactic acid yield but increased cellulose conversion. Semi-continuous simultaneous saccharification and co-fermentation (SSCF) using medium containing 100 g/L cellulose equivalent paper sludge without pH control was carried out in serum bottles for up to 1000 h. When rich medium was utilized, the average lactic acid concentrations in steady state for strains 36D1 and P4-102B were 92 g/L and 91.7 g/L, respectively, and lactic acid yields were 77% and 78%. The average lactic acid concentrations produced using semi-continuous SSCF with lean medium were 77.5 g/L and 77.0 g/L for strains 36D1 and P4-102B, respectively, and lactic acid yields were 72% and 75%. The productivities at steady state were 0.96 g/L/h and 0.82 g/L/h for both strains in rich medium and lean medium, respectively. Our data support that B. coagulan strains 36D1 and P4-102B are promising for converting paper sludge to lactic acid via SSCF. (C) 2009 Elsevier Ltd. All rights reserved.