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Isolation of cellulolytic bacteria from the intestine of Diatraea saccharalis larvae and evaluation of their capacity to degrade sugarcane biomass.

Dantur KI, Enrique R, Welin B, Castagnaro AP - AMB Express (2015)

Bottom Line: Bacterial growth on sugarcane biomass as well as extracellular endo-glucanase activity induced on soluble cellulose was found to be highest in species belonging to genera Bacillus and Klebsiella.Good cellulolytic activity correlated with high extracellular protein concentrations.In addition, scanning microscopy studies revealed attachment of cellulolytic strains to different sugarcane substrates.

View Article: PubMed Central - PubMed

Affiliation: Estación Experimental Agroindustrial Obispo Colombres (EEAOC) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Tecnología Agroindustrial del Noroeste Argentino (ITANOA), 3150 William Cross Av., Las Talitas, PC T4101XAC Tucumán Argentina.

ABSTRACT
As a strategy to find efficient lignocellulose degrading enzymes/microorganisms for sugarcane biomass pretreatment purposes, 118 culturable bacterial strains were isolated from intestines of sugarcane-fed larvae of the moth Diatraea saccharalis. All strains were tested for cellulolytic activity using soluble carboxymethyl cellulose (CMC) degrading assays or by growing bacteria on sugarcane biomass as sole carbon sources. Out of the 118 strains isolated thirty eight were found to possess cellulose degrading activity and phylogenetic studies of the 16S rDNA sequence revealed that all cellulolytic strains belonged to the phyla γ-Proteobacteria, Actinobacteria and Firmicutes. Within the three phyla, species belonging to five different genera were identified (Klebsiella, Stenotrophomonas, Microbacterium, Bacillus and Enterococcus). Bacterial growth on sugarcane biomass as well as extracellular endo-glucanase activity induced on soluble cellulose was found to be highest in species belonging to genera Bacillus and Klebsiella. Good cellulolytic activity correlated with high extracellular protein concentrations. In addition, scanning microscopy studies revealed attachment of cellulolytic strains to different sugarcane substrates. The results of this study indicate the possibility to find efficient cellulose degrading enzymes and microorganisms from intestines of insect larvae feeding on sugarcane and their possible application in industrial processing of sugarcane biomass such as second generation biofuel production.

No MeSH data available.


Related in: MedlinePlus

Neighbour-joining phylogenetic tree using the16S rDNAgene for sequence homology studies. A phylogenetic relationship from the 38 isolates showing growth and cellulolytic activity on biomass from sugarcane and CMC. Sequences of reference strains obtained from DNA databases are indicated in bold and accession numbers are given in parenthesis. Bacterial isolates outlined in top, middle and bottom groups belong to the phylum Proteobacteria, Firmicutes and Actinobacteria respectively. The scale represents 0.01 substitutions per nucleotide position. Bootstrap values are based on 1,000 replicates.
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Fig2: Neighbour-joining phylogenetic tree using the16S rDNAgene for sequence homology studies. A phylogenetic relationship from the 38 isolates showing growth and cellulolytic activity on biomass from sugarcane and CMC. Sequences of reference strains obtained from DNA databases are indicated in bold and accession numbers are given in parenthesis. Bacterial isolates outlined in top, middle and bottom groups belong to the phylum Proteobacteria, Firmicutes and Actinobacteria respectively. The scale represents 0.01 substitutions per nucleotide position. Bootstrap values are based on 1,000 replicates.

Mentions: The corresponding phylogenetic analysis based on the 16S rDNA gene sequences obtained is presented in Figure 2 where the homology tree shows two main groups, Gram-negative and Gram-positive bacteria. The former group contained isolates belonging to the phylum Proteobacteria, which included species from genera Stenotrophomonas (5.2%) and Klebsiella (47.4%). The Gram-positive group included bacteria belonging to the phyla Actinobacteria, represented by species of the genus Microbacterium (13.2%), and Firmicutes represented by species of the two genera, Enterococcus (23.7%) and Bacillus (10.5%).Figure 2


Isolation of cellulolytic bacteria from the intestine of Diatraea saccharalis larvae and evaluation of their capacity to degrade sugarcane biomass.

Dantur KI, Enrique R, Welin B, Castagnaro AP - AMB Express (2015)

Neighbour-joining phylogenetic tree using the16S rDNAgene for sequence homology studies. A phylogenetic relationship from the 38 isolates showing growth and cellulolytic activity on biomass from sugarcane and CMC. Sequences of reference strains obtained from DNA databases are indicated in bold and accession numbers are given in parenthesis. Bacterial isolates outlined in top, middle and bottom groups belong to the phylum Proteobacteria, Firmicutes and Actinobacteria respectively. The scale represents 0.01 substitutions per nucleotide position. Bootstrap values are based on 1,000 replicates.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385043&req=5

Fig2: Neighbour-joining phylogenetic tree using the16S rDNAgene for sequence homology studies. A phylogenetic relationship from the 38 isolates showing growth and cellulolytic activity on biomass from sugarcane and CMC. Sequences of reference strains obtained from DNA databases are indicated in bold and accession numbers are given in parenthesis. Bacterial isolates outlined in top, middle and bottom groups belong to the phylum Proteobacteria, Firmicutes and Actinobacteria respectively. The scale represents 0.01 substitutions per nucleotide position. Bootstrap values are based on 1,000 replicates.
Mentions: The corresponding phylogenetic analysis based on the 16S rDNA gene sequences obtained is presented in Figure 2 where the homology tree shows two main groups, Gram-negative and Gram-positive bacteria. The former group contained isolates belonging to the phylum Proteobacteria, which included species from genera Stenotrophomonas (5.2%) and Klebsiella (47.4%). The Gram-positive group included bacteria belonging to the phyla Actinobacteria, represented by species of the genus Microbacterium (13.2%), and Firmicutes represented by species of the two genera, Enterococcus (23.7%) and Bacillus (10.5%).Figure 2

Bottom Line: Bacterial growth on sugarcane biomass as well as extracellular endo-glucanase activity induced on soluble cellulose was found to be highest in species belonging to genera Bacillus and Klebsiella.Good cellulolytic activity correlated with high extracellular protein concentrations.In addition, scanning microscopy studies revealed attachment of cellulolytic strains to different sugarcane substrates.

View Article: PubMed Central - PubMed

Affiliation: Estación Experimental Agroindustrial Obispo Colombres (EEAOC) - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Tecnología Agroindustrial del Noroeste Argentino (ITANOA), 3150 William Cross Av., Las Talitas, PC T4101XAC Tucumán Argentina.

ABSTRACT
As a strategy to find efficient lignocellulose degrading enzymes/microorganisms for sugarcane biomass pretreatment purposes, 118 culturable bacterial strains were isolated from intestines of sugarcane-fed larvae of the moth Diatraea saccharalis. All strains were tested for cellulolytic activity using soluble carboxymethyl cellulose (CMC) degrading assays or by growing bacteria on sugarcane biomass as sole carbon sources. Out of the 118 strains isolated thirty eight were found to possess cellulose degrading activity and phylogenetic studies of the 16S rDNA sequence revealed that all cellulolytic strains belonged to the phyla γ-Proteobacteria, Actinobacteria and Firmicutes. Within the three phyla, species belonging to five different genera were identified (Klebsiella, Stenotrophomonas, Microbacterium, Bacillus and Enterococcus). Bacterial growth on sugarcane biomass as well as extracellular endo-glucanase activity induced on soluble cellulose was found to be highest in species belonging to genera Bacillus and Klebsiella. Good cellulolytic activity correlated with high extracellular protein concentrations. In addition, scanning microscopy studies revealed attachment of cellulolytic strains to different sugarcane substrates. The results of this study indicate the possibility to find efficient cellulose degrading enzymes and microorganisms from intestines of insect larvae feeding on sugarcane and their possible application in industrial processing of sugarcane biomass such as second generation biofuel production.

No MeSH data available.


Related in: MedlinePlus