Reducing Bacterial Contamination in Fuel Ethanol Fermentations by Ozone Treatment of Uncooked Corn Mash

Abstract Background Commercial ethanol fermentation facilities traditionally rely on antibiotics for bacterial contamination control. Here we demonstrate an alternative approach to treat contamination using a novel peptidoglycan hydrolase (LysKB317) isolated from a bacteriophage, EcoSau. This endolysin was specially selected against Lactobacillus strains that were isolated as contaminants from a fuel ethanol plant. The LysKB317 gene was recombinantly expressed in Escherichia coli as a 33 kDa purified enzyme. Results In turbidity reduction assays, the recombinant enzyme was subjected to a panel of 32 bacterial strains and was active against 28 bacterial strains representing one species of Acetobacter, eight species of Lactobacillus, one species of Pediococcus, three species of Streptococcus, and one species of Weissella. The activity of LysKB317 was optimal around pH 6, but it has broad activity and stability from pH 4.5 – 7.5 up to at least 48 h. Maximum activity was observed at 50°C up to at least 72 h. In addition, LysKB317 was stable in 30% ethanol up to at least 72 h. In experimentally infected corn mash fermentations, 1 µM endolysin reduced bacterial load by 4-log fold change, while 0.01 µM reduced bacteria by 2-log fold change. Concentration of fermentation products (ethanol, residual glucose, lactic acid, and acetic acids) for infected cultures treated with ≥ 0.01 µM LysKB317 were similar to uncontaminated controls. Conclusion Exogenously added LysKB317 endolysin is functional in conditions typically found in fuel ethanol fermentations tanks and may be developed as an alternative to antibiotics for contamination control during fuel ethanol fermentations.

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Controlling Bacterial Contamination During Fuel Ethanol Fermentation Using Thermochemically Depolymerized Lignin Bio-Oils

Green Chemistry ◽

10.1039/d1gc01521d ◽

2021 ◽

Author(s):

Ryan M Kalinoski ◽

Wenqi Li ◽

Justin K Mobley ◽

Xiaowen Chen ◽

Sue E Nokes ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Ethanol Fermentation ◽

Bacterial Contamination ◽

Fuel Ethanol

Lactic acid bacteria (LAB) contamination during fuel ethanol fermentation can lead to significant economic loses. To circumvent this, fuel ethanol plants add antibiotics prophylactically, but their overuse has resulted in...

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Recombinant bacteriophage LysKB317 endolysin mitigates Lactobacillus infection of corn mash fermentations

Biotechnology for Biofuels ◽

10.1186/s13068-020-01795-9 ◽

2020 ◽

Vol 13 (1) ◽

Author(s):

Shao-Yeh Lu ◽

Kenneth M. Bischoff ◽

Joseph O. Rich ◽

Siqing Liu ◽

Christopher D. Skory

Keyword(s):

Bacterial Load ◽

Fuel Ethanol ◽

Maximum Activity ◽

Fold Change ◽

Bacterial Strains ◽

Fermentation Products ◽

Contamination Control ◽

Alternative Approach ◽

Residual Glucose ◽

Corn Mash

Abstract Background Commercial ethanol fermentation facilities traditionally rely on antibiotics for bacterial contamination control. Here we demonstrate an alternative approach to treat contamination using a novel peptidoglycan hydrolase (LysKB317) isolated from a bacteriophage, EcoSau. This endolysin was specially selected against Lactobacillus strains that were isolated as contaminants from a fuel ethanol plant. The LysKB317 gene was recombinantly expressed in Escherichia coli as a 33 kDa purified enzyme. Results In turbidity reduction assays, the recombinant enzyme was subjected to a panel of 32 bacterial strains and was active against 28 bacterial strains representing 1 species of Acetobacter, 8 species of Lactobacillus, 1 species of Pediococcus, 3 species of Streptococcus, and 1 species of Weissella. The activity of LysKB317 was optimal around pH 6, but it has broad activity and stability from pH 4.5–7.5 up to at least 48 h. Maximum activity was observed at 50 °C up to at least 72 h. In addition, LysKB317 was stable in 30% ethanol up to at least 72 h. In experimentally infected corn mash fermentations, 1 µM endolysin reduced bacterial load by 3-log fold change, while 0.01 µM reduced bacteria by 2-log fold change. Concentration of fermentation products (ethanol, residual glucose, lactic acid, and acetic acids) for infected cultures treated with ≥ 0.01 µM LysKB317 was similar to uncontaminated controls. Conclusion Exogenously added LysKB317 endolysin is functional in conditions typically found in fuel ethanol fermentations tanks and may be developed as an alternative to antibiotics for contamination control during fuel ethanol fermentations.

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Resolving bacterial contamination of fuel ethanol fermentations with beneficial bacteria – An alternative to antibiotic treatment

Bioresource Technology ◽

10.1016/j.biortech.2017.09.067 ◽

2018 ◽

Vol 247 ◽

pp. 357-362 ◽

Cited By ~ 16

Author(s):

Joseph O. Rich ◽

Kenneth M. Bischoff ◽

Timothy D. Leathers ◽

Amber M. Anderson ◽

Siqing Liu ◽

...

Keyword(s):

Antibiotic Treatment ◽

Bacterial Contamination ◽

Fuel Ethanol ◽

Beneficial Bacteria

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Conventional and nonconventional strategies for controlling bacterial contamination in fuel ethanol fermentations

World Journal of Microbiology and Biotechnology ◽

10.1007/s11274-018-2463-2 ◽

2018 ◽

Vol 34 (6) ◽

Cited By ~ 10

Author(s):

Sandra Regina Ceccato-Antonini

Keyword(s):

Bacterial Contamination ◽

Fuel Ethanol

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Recombinant Bacteriophage LysKB317 Endolysin Mitigates Lactobacillus Infection of Corn Mash Fermentations

10.21203/rs.3.rs-38124/v2 ◽

2020 ◽

Author(s):

Shao- Yeh Lu ◽

Kenneth M. Bischoff ◽

Joseph O. Rich ◽

Siqing Liu ◽

Christopher D. Skory

Keyword(s):

Bacterial Load ◽

Fuel Ethanol ◽

Maximum Activity ◽

Fold Change ◽

Bacterial Strains ◽

Fermentation Products ◽

Contamination Control ◽

Alternative Approach ◽

Residual Glucose ◽

Corn Mash

Abstract Background Commercial ethanol fermentation facilities traditionally rely on antibiotics for bacterial contamination control. Here we demonstrate an alternative approach to treat contamination using a novel peptidoglycan hydrolase (LysKB317) isolated from a bacteriophage, EcoSau. This endolysin was specially selected against Lactobacillus strains that were isolated as contaminants from a fuel ethanol plant. The LysKB317 gene was recombinantly expressed in Escherichia coli as a 33 kDa purified enzyme. Results In turbidity reduction assays, the recombinant enzyme was subjected to a panel of 32 bacterial strains and was active against 28 bacterial strains representing one species of Acetobacter, eight species of Lactobacillus, one species of Pediococcus, three species of Streptococcus, and one species of Weissella. The activity of LysKB317 was optimal around pH 6, but it has broad activity and stability from pH 4.5 – 7.5 up to at least 48 h. Maximum activity was observed at 50°C up to at least 72 hrs. In addition, LysKB317 was stable in 30% ethanol up to at least 72 hrs. In experimentally infected corn mash fermentations, 1 µM endolysin reduced bacterial load by 3-log fold change, while 0.01 µM reduced bacteria by 2-log fold change. Concentration of fermentation products (ethanol, residual glucose, lactic acid, and acetic acids) for infected cultures treated with ≥ 0.01 µM LysKB317 were similar to uncontaminated controls. Conclusion Exogenously added LysKB317 endolysin is functional in conditions typically found in fuel ethanol fermentations tanks and may be developed as an alternative to antibiotics for contamination control during fuel ethanol fermentations.

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PLASMA-CHEMICAL METHODS FOR CONTROL OF BIOTIC CONTAMINANTS

10.46813/2019-122-198 ◽

2019 ◽

pp. 198-202

Author(s):

G.V. Taran ◽

V.A. Breslavets ◽

A.A. Zamuriev ◽

M.O. Yaroshenko ◽

P.O. Opalev ◽

...

Keyword(s):

Bacterial Contamination ◽

Chemical Reactor ◽

Ozone Treatment ◽

Oh Radicals ◽

Microscopic Fungi ◽

Plasma Chemical ◽

Chemical Methods ◽

Egg Shell ◽

Hatching Eggs ◽

Methods Of Treatment

The possibility and effectiveness of control of biotic contaminants (bacteria, micromycetes) with ozone and air activated by the plasma chemical reactor were studied as an alternative to the chemical methods of treatment using the model of hatching eggs. It was shown that as a result of the egg shell ozone treatment, bacterial contamination decreased by 3083 times after four days of treatment, and the level of microbiota decreased by 2.6 times after five days of treatment. As a result of the egg shell air treatment, bacterial contamination decreased by 30.56 times after three days of treatment, and the level of contamination with microscopic fungi decreased by 6.9 times on the fifth day of treatment. As the amount of OH radicals in the activated air increased, the level of bacterial culture decreased by 60 times on the third day of treatment, and the level of egg shell contamination with microscopic fungi decreased by 7.2 times on the fifth day of treatment.

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