Isolation and characterization of novel 1,3-propanediol-producing Lactobacillus panis PM1 from bioethanol thin stillage.
Conversion of glycerol to 1,3-propanediol (1,3-PDO) is an attractive option to increase the economic efficiency of the biofuel industry. A bacterial strain that produced 1,3-PDO in the presence of glycerol was isolated from thin stillage, the fermentation residue of bioethanol production. This 1,3-PDO-producing organism was identified as Lactobacillus panis through biochemical characteristics and by 16S rRNA sequencing. Characterization of the L. panis strain hereafter designated as PM1 revealed it was an aerotolerant acidophilic anaerobe able to grow over a wide range of temperatures; tolerant to high concentrations of sodium chloride, ethanol, acetic acid, and lactic acid; and resistant to many common antibiotics. L. panis PM1 could utilize glucose, lactose, galactose, maltose, xylose, and arabinose, but could not grow on sucrose or fructose. Production of 1,3-PDO by L. panis PM1 occurred only when glucose was available as the carbon source in the absence of oxygen. These metabolic characteristics strongly suggested NADH recycling for glucose metabolism is achieved through 1,3-PDO production by this strain. These characteristics classified L. panis PM1 within the group III heterofermentative lactic acid bacteria, which includes the well-characterized 1,3-PDO-producing strain, Lactobacillus reuteri. Metabolite production profiles showed that L. panis PM1 produced considerable amounts of succinic acid (~11-12 mM) from normal MRS medium, which distinguishes this strain from L. reuteri strains.
Department of Food and Bioproduct Sciences, College of Agriculture and Bioresources, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK, S7N 5A8, Canada.
Nurul H
NH
Khan
Tae Sun
TS
Kang
Douglas A S
DA
Grahame
Monique C
MC
Haakensen
Kornsulee
K
Ratanapariyanuch
Martin J
MJ
Reaney
Darren R
DR
Korber
Takuji
T
Tanaka
D000693:Anaerobiosis; D015373:Bacterial Typing Techniques; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D007778:Lactobacillus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D011409:Propylene Glycols / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D011409:Propylene Glycols; D012336:RNA, Ribosomal, 16S; C041787:1,3-propanediol; D005947:Glucose; D005990:Glycerol