CAJ | 학술논문

纤维素油脂的统合生物加工过程是将纤维素酶生产、纤维素水解和微生物油脂发酵过程组合,通过一种微生物完成.运用统合生物加工过程生产微生物油脂可以降低生物转化过程的成本.该文对20株纤维素降解菌进行筛选评价,结果发现青霉菌株 P‐2同时具备有效的纤维素降解和油脂积累能力.脂肪酸组分分析表明,菌株 P‐2胞内油脂的脂肪酸组分主要为棕榈酸( C16：0,21.05％)、油酸( C18：1,22.43％)和亚油酸( C18：2,27.78％).菌株P‐2在以纤维素粉为底物的液体发酵和以秸秆、麸皮混合物为底物的固态发酵条件下可达到的最高油脂产量分别为0.65 g/L 和40.13 mg/g(按干物质计).说明青霉 P‐2是一株潜在的低成本纤维素油脂生产菌.进一步分析在发酵试验中的油脂产量和纤维素酶活力发现,菌株 P‐2的纤维素酶分泌能力在其油脂生产过程中具有重要作用.外源纤维素酶添加试验证实,在培养基中外源纤维素酶添加量的提高可以促进 P‐2油脂的生产.添加24 IU /g (按干物质计)纤维素酶可使 P‐2发酵后的最高油脂产量达到0.83 g/L .对固态发酵所得到的滤纸酶活力和油脂产量数据进行相关分析,结果证实滤纸酶活力与油脂产量之间存在极显著的正相关关系( R2＝0.711,P＜0.01).当固态发酵系统中的滤纸酶活力从1.0 IU /g 增加到3.5 IU /g(按干物质计)时,对应的油脂产量从26.24 mg/g上升到40.13 mg/g(按干物质计),产量增长量达到52.93％.以上结果暗示纤维素酶分泌能力不足是制约 P‐2油脂产量的一个重要原因；因此,通过调控菌株 P‐2的纤维素酶分泌能力可能是提高油脂产量的可行性策略之一.
섬유소유지적통합생물가공과정시장섬유소매생산、섬유소수해화미생물유지발효과정조합,통과일충미생물완성.운용통합생물가공과정생산미생물유지가이강저생물전화과정적성본.해문대20주섬유소강해균진행사선평개,결과발현청매균주 P‐2동시구비유효적섬유소강해화유지적루능력.지방산조분분석표명,균주 P‐2포내유지적지방산조분주요위종려산( C16：0,21.05％)、유산( C18：1,22.43％)화아유산( C18：2,27.78％).균주P‐2재이섬유소분위저물적액체발효화이갈간、부피혼합물위저물적고태발효조건하가체도적최고유지산량분별위0.65 g/L 화40.13 mg/g(안간물질계).설명청매 P‐2시일주잠재적저성본섬유소유지생산균.진일보분석재발효시험중적유지산량화섬유소매활력발현,균주 P‐2적섬유소매분비능력재기유지생산과정중구유중요작용.외원섬유소매첨가시험증실,재배양기중외원섬유소매첨가량적제고가이촉진 P‐2유지적생산.첨가24 IU /g (안간물질계)섬유소매가사 P‐2발효후적최고유지산량체도0.83 g/L .대고태발효소득도적려지매활력화유지산량수거진행상관분석,결과증실려지매활력여유지산량지간존재겁현저적정상관관계( R2＝0.711,P＜0.01).당고태발효계통중적려지매활력종1.0 IU /g 증가도3.5 IU /g(안간물질계)시,대응적유지산량종26.24 mg/g상승도40.13 mg/g(안간물질계),산량증장량체도52.93％.이상결과암시섬유소매분비능력불족시제약 P‐2유지산량적일개중요원인；인차,통과조공균주 P‐2적섬유소매분비능력가능시제고유지산량적가행성책략지일.
Summary Consolidated bioprocessing (CBP) is a convenient and cost‐efficient strategy to produce single cell oils ( SCOs ) from cellulose‐based substrates . In this study , Penicillium P‐2 having both effective cellulose degradation and lipid accumulation was isolated from 20 cellulolytic fungi . The SCOs of the strain P‐2 were mainly composed of palmitic acid ( C16 :0 , 21 .05% ) , oleic acid ( C18 :1 , 22 .43% ) and linoleic acid ( C18 :2 , 27 .78% ) . Fermentation experiments of the strain P‐2 showed that maximum lipid yields of 0 .65 g/L and 40 .13 mg/g ( per gram dry mass of initial solid substrate) could be obtained by submerged fermentation ( SmF) from cellulose and solid‐state fermentation (SSF) from wheat straw and bran mixture , respectively . The results from the two CBP indicated that the strain P‐2 had a potential to be a promising low‐cost oil producer using cellulose‐based substrates . The further analysis for lipid accumulation and cellulase secretion of the strain P‐2 suggested that the cellulase secretion of the strain P‐2 might play a key role in the lipid production . The submerged fermentation with exogenous cellulase addition by the strain P‐2 demonstrated that the higher exogenous cellulase dosages could lead to higher lipid production and the lipid yield would increase up to 0 .83 g/L with the addition of 24 IU /g cellulase . A highly significant positive correlation between the filter paper activity ( FPA) and the lipid yield in the strain P‐2 was further observed on the data pooled from the SSF parameter treatments ( P < 0 .01) . When the detected FPA in SSF system increased from 1 .0 IU /g to 3 .5 IU /g , the lipid yield was also increased from 26 .24 mg/g to 40 .13 mg/g with the increment of 52 .93% . All these analyses suggest that the weak cellulase secretion of the strain P‐2 is an important cause of the low lipid yield , so the regulation of endogenous cellulase secretion might be a feasible strategy for enhancing lipid production of the strain P‐2 .