Abstract: Ethanol losses due to bacterial contamination in fermentation cultures weakens the economics of biofuel production. Lactobacillus species are the predominant contaminant. Bacteriophage lytic enzymes are peptidoglycan hydrolases which degrade Gram positive cell walls when exposed externally and are a novel source of antimicrobials. The streptococcal phage ?SA2 endolysin construct demonstrated strong lytic activity towards 17 of 22 strains of lactobacilli, staphylococci or streptococci maintaining optimal specific activity under fermentation conditions toward L. fermentum substrates. Lactobacillus bacteriophage endolysin constructs LysA, LysA2 and LysgaY showed exolytic activity towards ˜60% of the lactobacilli tested including four L. fermentum isolates from fuel ethanol fermentations. Presence of ethanol (?5%) did not affect lytic activity. Lysins were able to reduce both L. fermentum and L. reuteri contaminants in mock fermentations of corn fiber hydrolysates.

Abstract: Described are novel Kluyveromyces marxianus strains NRRL Y-50798 and Y-50799, that were obtained by UV-C irradiation of wild-type K. marxianus NRRL Y-1109 cultures. The UV-C-mutagenized strains were incubated under anaerobic conditions on xylose or glucose medium for a period of 5 months at 46° C. before being selected. These mutagenized strains have potential application in large-scale industrial conversion of lignocellulosic sugars to fuel ethanol given their ability to ferment at temperatures at 46° C. and above.

Abstract: Described are novel S. stipitis strains that were obtained by UV-C irradiation of wild-type S. stipitis NRRL Y-7124 cultures, followed by 5-month anaerobic growth on xylose at 28° C. The UV-C-mutagenized strains were able to grow anaerobically on xylose or glucose medium with higher ethanol production than a Saccharomyces cerevisiae yeast strain under comparable fermentation conditions. The mutagenized strains were identified by DNA fingerprinting to be unique strains closely related to wild-type Scheffersomyces stipitis. These mutagenized strains have potential application in large-scale industrial conversion of lignocellulosic sugars to fuel ethanol.

Abstract: Recombinant Saccharomyces cerevisiae produced by transformation with heterologous polynucleotide sequences coding for xylulokinase (XKS) from Yersinia pestis and xylose isomerase (XI) are capable of xylose utilization. The transformants express these heterologous polynucleotides at a sufficient functional level to grow aerobically on xylose as the sole carbon source. Further transformation of the recombinant yeasts to overexpress one or more of the S cerevisiae genes PIP2, IMG2, MAK5, VPS9, COX10, ALE1, CDC7, and MMS4, permits the yeast to grow anaerobically on xylose as the sole carbon source. When grown under anaerobic conditions on a culture medium comprising both glucose and xylose, the transformed yeast exhibit increased ethanol productivity, with the yeast growing on the xylose to increase their biomass and fermenting the glucose to ethanol.

Abstract: Lycotoxin-1 peptide mutant peptides which exhibit increased insecticidal activity are produced by substitution of both a proline for the lysine at amino acid position 24 and a tryptophan for the leucine at amino acid position 25 of the wild-type amino acid sequence for lycotoxin-1. Further substitution of amino acids 8, 9 or 10 of the lycotoxin-1 wild-type amino acid sequence, specifically substituting a histidine for the phenylalanine at amino acid position 8, a glutamine for the glycine at amino acid position 10, or a serine for the leucine at amino acid position 9, provides an even greater increase in insecticidal activity. In addition to changes in the lycotoxin-1 amino acid sequence, the addition of an enterokinase K recognition site, DDDK, to the N-terminus of the lycotoxin-1 peptide increases insecticidal activity further still.

Abstract: Recombinant Saccharomyces cerevisiae produced by transformation with heterologous polynucleotide sequences coding for xylulokinase (XKS) from Yersinia pestis and xylose isomerase (XI) are capable of xylose utilization. The transformants express these heterologous polynucleotides at a sufficient functional level to grow aerobically on xylose as the sole carbon source. Further transformation of the recombinant yeasts to overexpress one or more of the S cerevisiae genes PIP2, IMG2, MAK5, VPS9, COX10, ALE1, CDC7, and MMS4, permits the yeast to grow anaerobically on xylose as the sole carbon source. When grown under anaerobic conditions on a culture medium comprising both glucose and xylose, the transformed yeast exhibit increased ethanol productivity, with the yeast growing on the xylose to increase their biomass and fermenting the glucose to ethanol.