Isolation, characterization and application of a cellulose-degrading strain Neurospora crassa S1 from oil palm empty fruit bunch.
BACKGROUND
Oil palm empty fruit bunch (EFB) is a lignocellulosic waste produced in palm oil industry. EFB mainly consists of cellulose, hemicellulose (mainly xylan) and lignin and has a great potential to be reused. Converting EFB to fermentable sugars and value-added chemicals is a much better choice than treating EFB as waste.


RESULTS
A cellulase-producing strain growing on oil palm empty fruit bunch (EFB) was isolated and identified as Neurospora crassa S1, which is able to produce cellulases using EFB as the sole carbon source. The strain started to secret cellulases into the medium after 24 h of cultivation at 30°C and reached its maximal cellulase activity at 240 h. Mass spectroscopy (MS) analysis showed that more than 50 proteins were secreted into the medium when EFB was used as the sole carbon source. Among them, 7 proteins were identified as putative enzymes associated with cellulose degradation. The whole cell culture of Neurospora crassa S1 was used to hydrolyze acid-treated EFB, giving a total sugar yield of 83.2%, which is comparable with that (82.0%) using a well-known cellulase producer Trichoderma reesei RUT-C30 (ATCC56765).


CONCLUSIONS
Neurospora crassa S1 is a commercially promising native cellulase producer for EFB hydrolysis especially when the sugars obtained are to be fermented to products that require use of non-genetically engineered strains.
Institute of Chemical & Engineering Sciences, Agency for Science, Technology and Research, 1 Pesek Road, Jurong Island, Singapore, 627833, Singapore. li_qingxin@ices.a-star.edu.sg.
Qingxin
Q
Li
Institute of Chemical & Engineering Sciences, Agency for Science, Technology and Research, 1 Pesek Road, Jurong Island, Singapore, 627833, Singapore. cindy_ng@ices.a-star.edu.sg.
Wei Ting
WT
Ng
Institute of Chemical & Engineering Sciences, Agency for Science, Technology and Research, 1 Pesek Road, Jurong Island, Singapore, 627833, Singapore. wu_jinchuan@ices.a-star.edu.sg.
Jin Chuan
JC
Wu
D044602:Cellulases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D005638:Fruit / Q000382:microbiology; D005656:Fungal Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D008031:Lignin / Q000378:metabolism*; D009492:Neurospora crassa / Q000201:enzymology / Q000254:growth & development / Q000302:isolation & purification; D000073878:Palm Oil; D010938:Plant Oils
D005656:Fungal Proteins; D010938:Plant Oils; C036909:lignocellulose; D000073878:Palm Oil; D008031:Lignin; D044602:Cellulases