TY - JOUR
T1 - An effective microplate method (Biolog MT2) for screening native lignocellulosic-straw-degrading bacteria
AU - Taha, Mohamed
AU - Kadali, Krishna K.
AU - AL-Hothaly, Khalid
AU - Smith, Andrew T.
AU - Ball, Andrew S.
AU - Adetutu, Eric M.
N1 - Funding Information:
Acknowledgments The authors are grateful to RMIT University and the Egyptian Government for the provision of a PhD scholarship to Mohamed Taha. The authors also acknowledge the facilities, and the scientific and technical assistance, of the Australian Microscopy & Microanalysis Research Facility (AMMRF) at the RMIT Microscopy & Microanalysis Facility, at RMIT University.
PY - 2015/12/1
Y1 - 2015/12/1
N2 - Lignocellulosic wastes such as straw are attractive resources for biofuel production when subjected to biological treatment (hydrolysis). However, their complex lignocellulosic structure can hinder saccharification. The urgent need for microbial groups with high levels of straw saccharifying activities is therefore a key step in the bioconversion of lignocellulosic straw into fermentable monosaccharides. Existing traditional methods of qualitative and quantitative screening of lignocellulolytic microbial isolates are costly, time consuming and largely not environmentally friendly. In this study, a Biolog (MT2) microplate-based assay was evaluated for potential use as an alternative screening method. This was carried out using three commercially available substrates (cellulose, xylan and lignin) and four native lignocellulosic straws (wheat, rice, sugarcane, and pea ball-milled straws). Selected bacterial isolates from soil, compost and straws were screened quantitatively using both traditional crude enzyme and Biolog (MT2) microplate methods. Positive correlations (R2 values up to 0.86) between Biolog and the traditional enzyme methodologies were observed with respect to these isolates and their lignocellulosic activities. Quantitative assays were less labor intensive and faster (3–7 days) in Biolog microplates than in traditional assays which lasted for 12–15 days. Ball-milled rice and sugarcane straws were bio-converted to monosaccharaides more readily than wheat and pea straws and the commercially available substrates (cellulose, xylan and lignin). Environmental scanning electron microscopy (ESEM) analysis of ball-milled rice and sugarcane straws suggested that this was due to their higher silica content. Overall, the Biolog (MT2) microplate system was shown to be an effective, time saving and inexpensive alternative method for the screening of both lignocellulose-degrading bacteria and different substrates for saccharification.
AB - Lignocellulosic wastes such as straw are attractive resources for biofuel production when subjected to biological treatment (hydrolysis). However, their complex lignocellulosic structure can hinder saccharification. The urgent need for microbial groups with high levels of straw saccharifying activities is therefore a key step in the bioconversion of lignocellulosic straw into fermentable monosaccharides. Existing traditional methods of qualitative and quantitative screening of lignocellulolytic microbial isolates are costly, time consuming and largely not environmentally friendly. In this study, a Biolog (MT2) microplate-based assay was evaluated for potential use as an alternative screening method. This was carried out using three commercially available substrates (cellulose, xylan and lignin) and four native lignocellulosic straws (wheat, rice, sugarcane, and pea ball-milled straws). Selected bacterial isolates from soil, compost and straws were screened quantitatively using both traditional crude enzyme and Biolog (MT2) microplate methods. Positive correlations (R2 values up to 0.86) between Biolog and the traditional enzyme methodologies were observed with respect to these isolates and their lignocellulosic activities. Quantitative assays were less labor intensive and faster (3–7 days) in Biolog microplates than in traditional assays which lasted for 12–15 days. Ball-milled rice and sugarcane straws were bio-converted to monosaccharaides more readily than wheat and pea straws and the commercially available substrates (cellulose, xylan and lignin). Environmental scanning electron microscopy (ESEM) analysis of ball-milled rice and sugarcane straws suggested that this was due to their higher silica content. Overall, the Biolog (MT2) microplate system was shown to be an effective, time saving and inexpensive alternative method for the screening of both lignocellulose-degrading bacteria and different substrates for saccharification.
KW - Bacterial screening
KW - Ball-milled straw
KW - Biolog (MT2) microplate
KW - Correlation analysis
KW - Lignocellulose degradation
UR - http://www.scopus.com/inward/record.url?scp=84957432734&partnerID=8YFLogxK
U2 - 10.1007/s13213-015-1044-y
DO - 10.1007/s13213-015-1044-y
M3 - Article
AN - SCOPUS:84957432734
VL - 65
SP - 2053
EP - 2064
JO - Annals of Microbiology
JF - Annals of Microbiology
SN - 1590-4261
IS - 4
ER -