Abstract
Bacterial contamination of commercial fermentation cultures is a common and costly problem to the fuel ethanol industry. Antimicrobials such as virginiamycin (VIR) and penicillin (PEN) are frequently used to control contamination but there are little data available on the susceptibility of bacterial contaminants to these agents. A survey of bacterial contaminants from a wet-mill ethanol plant with no history of using antibiotics and a dry-grind facility that periodically doses with VIR found that the majority of contaminants were species of Lactobacillus. Thirty-seven isolates of Lactobacillus species from the wet-mill and 42 isolates from the dry-grind facility were tested for antimicrobial susceptibility using broth dilution and agar dilution methods. In general, the Lactobacillus isolates from the dry-grind plant had higher minimum inhibitory concentrations (MICs) for the tested agents than the isolates from the wet-mill facility. The MIC90 for VIR was 4 μg/ml for the dry-grind isolates versus 0.25 μg/ml for the wet-mill isolates; and for PEN, the MIC90’s were >8 and 2 μg/ml for the dry-grind and wet-mill isolates, respectively. Sixteen Lactobacillus isolates from the dry-grind plant but none from the wet-mill possessed vatE, a gene that encodes a streptogramin acetyltransferase associated with resistance to virginiamycin. Despite decreased susceptibility to virginiamycin, most dry-grind isolates had MICs lower than the maximal recommended application rate of 6 ppm.
Similar content being viewed by others
References
Altschul SF, Madden TL, Schäffer AA, Zhang J, Zhang Z, Miller W, Lipman DJ (1997) Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Res 25:3389–3402
Anonymous (2003) Opinion of the Scientific Committee on Animal Nutrition on the criteria for assessing the safety on micro-organisms resistant to antibiotics of human clinical and veterinary importance. European Commission Health & Consumer Protection Directorate-General, Brussels. Available at http://www.ec.europa.eu/food/fs/sc/scan/out108_en.pdf
Aquarone E (1960) Penicillin and tetracycline as contamination control agents in alcoholic fermentation of sugar cane molasses. Appl Microbiol 8:263–268
Bass L, Liebert CA, Lee MD, White DG, Summers AO, Thayer SG, Maurer JJ (1999) The incidence and characterization of integrons, genetic elements associated with multiple drug resistance, in avian Escherichia coli. Antimicrob Agents Chemother 43:2925–2929
Bayrock DP, Thomas KC, Ingledew WM (2003) Control of Lactobacillus contaminants in continuous fuel ethanol fermentations by constant or pulsed addition of penicillin G. Appl Microbiol Biotechnol 62:498–502
Boyd MA, Antonio MAD, Hillier SL (2005) Comparison of API 50 CH strips to whole-chromosomal DNA probes for identification of Lactobacillus species. J Clin Microbiol 43:5309–5311
Connolly C (1997) Bacterial contaminants and their effects on alcohol production. In: Jacques KA, Lyons TP, Kelsall DR (eds) The alcohol textbook, 3rd edn. Nottingham University Press, Nottingham, UK, pp 317–334
Danielson M, Wind A (2003) Susceptiblity of Lactobacillus spp. to antimicrobial agents. Int J Food Microbiol 82:1–11
Day WH, Serjak WC, Stratton JR, Stone L (1954) Antibiotics as contamination-control agents in grain alcohol fermentations. J Agric Food Chem 2:252–258
De Meester C, Rodelet J (1976) Microbial acetylation of M factor of virginiamycin. J Antibiot 29:1297–1305
Florez AB, Delgada S, Mayo B (2005) Antimicrobial susceptibility of lactic acid bacterial isolated from a cheese environment. Can J Microbiol 51:51–58
Gfeller KY, Roth M, Meile L, Teuber M (2003) Sequence and genetic organization of the 19.3-kb erythromycin- and dalfopristin-resistance plasmid pLME300 from Lactobacillus fermentum ROT1. Plasmid 50:190–201
Horz HP, Vianna ME, Gomes BPFA, Conrads G (2005) Evaluation of universal probes and primer sets for assessing total bacterial load in clinical samples: general implications and practical use in endodontic antimicrobial therapy. J Clin Microbiol 43:5332–5337
Huys G, Vancanneyt M, D’Haene K, Vankerckhoven V, Goossens H, Swings J (2006) Accuracy of species identity of commercial bacterial cultures intended for probiotic or nutritional use. Res Microbiol 157:803–810
Hynes SH, Kjarsgaard DM, Thomas KC, Ingledew WM (1997) Use of virginiamycin to control the growth of lactic acid bacteria during alcohol fermentation. J Ind Microbiol Biotechnol 18:284–291
Khan AA, Nawaz MS, Robertson L, Khan SA, Cerniglia CE (2001) Identification of predominant human and animal anaerobic intestinal bacterial species by terminal restriction fragment patterns (TRFPs): a rapid, PCR-based method. Mol Cell Probes 15:349–355
Lu J, Perng C, Lee S, Wan C (2000) Use of PCR with universal primers and restriction endonuclease digestions for detection and identification of common bacterial pathogens in cerebrospinal fluid. J Clin Microbiol 38:2076–2080
Lushia W, Heist P (2005) Antibiotic resistant bacteria in fuel ethanol fermentations. In: Ethanol Producer Magazine, pp 80–82
Makanjuola DB, Tymon A, Springham DG (1992) Some effects of lactic acid bacteria on laboratory-scale yeast fermentations. Enzyme Microbiol Technol 14:350–357
Nandi S, Maurer JJ, Hofacre C, Summers AO (2004) Gram-positive bacteria are a major reservoir of Class 1 antibiotic resistance integrons in poultry litter. Proc Natl Acad Sci USA 101:7118–7122
Narendranath NV, Hynes SH, Thomas KC, Ingledew WM (1997) Effects of lactobacilli on yeast-catalyzed ethanol fermentations. Appl Environ Microbiol 63:4158–4163
Narendranath NV, Thomas KC, Ingledew WM (2000) Urea hydrogen peroxide reduces the numbers of Lactobacilli, nourishes yeast, and leaves no residues in the ethanol fermentation. Appl Environ Microbiol 66:4187–4192
National Committee for Clinical Laboratory Standards (1999) Performance standards for antimicrobial disk and dilution susceptibility tests for bacteria isolated from animals; approved standard (M31-A). National Committee for Clinical Laboratory Standards, Wayne
Rende-Fournier R, Leclercq R, Galimand M, Duval J, Courvalin P (1993) Identification of the satA gene encoding a streptogramin A acetyltransferase in Enterococcus faecium BM4145. Antimicrob Agents Chemother 37:2119–2125
Rückle L, Senn T (2006) Hop acids can efficiently replace antibiotics in ethanol production. Int Sugar J 108:139–147
Skinner KA, Leathers TD (2004) Bacterial contaminants of fuel ethanol production. J Ind Microbiol Biotechnol 31:401–408
Soltani M, Beighton D, Philpott-Howard J, Woddford N (2000) Mechanisms of resistance to quinupristin-dalfopristin among isolates of Enterococcus faecium from animals, raw meat, and hospital patients in western Europe. Antimicrob Agents Chemother 44:433–436
Stroppa CT, Andrietta MGS, Andrietta SR, Steckelberg C, Serra GE (2000) Use of penicillin and monensin to control bacterial contamination of Brazilian alcohol fermentations. Int Sugar J 102:78–82
Werner G, Witte W (1999) Characterization of a new enterococcal gene, satG, encoding a putative acetyltransferase conferring resistance to streptogramin A compounds. Antimicrob Agents Chemother 43:1813–1814
Acknowledgments
The authors thank the fuel ethanol companies that participated in this study, who requested that their contributions remain anonymous. Expert technical assistance was provided by Melinda S. Nunnally, Eric Hoecker, and Imran Khan.
Author information
Authors and Affiliations
Corresponding author
Additional information
Mention of a trade name, proprietary product, or specific equipment does not constitute a guarantee or warranty by the United States Department of Agriculture and does not imply its approval to the exclusion of other products that may be suitable.
Rights and permissions
About this article
Cite this article
Bischoff, K.M., Skinner-Nemec, K.A. & Leathers, T.D. Antimicrobial susceptibility of Lactobacillus species isolated from commercial ethanol plants. J Ind Microbiol Biotechnol 34, 739–744 (2007). https://doi.org/10.1007/s10295-007-0250-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10295-007-0250-4