NABC Mash Bacterial Analysis Program

MBA is provided to quickly troubleshoot bacteria contamination and provide swift remedy so that yields are not lost. MBA assists the producer in reducing the duration and recurrence of contamination events by identifying the source location and an efficacious control method of the infection. Testing is done to determine the effectiveness of a variety of antibiotics against each bacterium isolated. The value to the customer is in reducing the duration of contamination events by identifying the location of bacteria and also which antibiotics will be most effective against the bacteria. A report is issued to the customer within 3 working days of sample receipt. Recommendation: Performed every 60 days and during contamination events.

Mash Bacterial Analysis Program Protocol:

When an ethanol plant has concerns of contamination, the plant should collect samples from a variety of locations to submit to NABC's laboratory for testing. Recommended sampling points include: mash train samples collected immediately before and after the beer/mash exchangers and mash cooler, fermentors. yeast propagator, and beerwell. Centrate and cook samples can be submitted but the occurrence of contamination in these samples is slight.

Sample kits are provided free of charge to the customer. These sample kits include a Styrofoam cooler, six sterile sample bottles, two freezer packs, submission form for samples, and detailed sample collection and transport instructions.

Each sample received will be microbiologically processed. Bacterial plating will include the following:

• Quantification of total bacterial population.
• Isolation of each individual organism present
• Susceptibility testing of eacli organism.
• Genetic ID (AVAILABLE FOR ADDITIONAL CHARGE).

An initial report will be sent to the customer within 3 working days of sample receipt. This report includes a thorough breakdown of the above 3 tests. A final and comprehensive report will be sent within 2 weeks of sample receipt with the additional genetic ID information. Explanations of the tests and reported results are as follows: 

-Quantification of total bacterial population. This represents a total bacteria count, including a segregation of anaerobic and aerobic bacteria counts. Each sample will have a result of total bacteria present and also discussion on acceptable upper limits of bacterial counts.

-Isolation of each individual organism present. The report lists each organism separately and also shows which bacteria isolates were found in which plant samples. This helps to identify the source of bacterial contamination from within the plant.

-Susceptibility testing of each organism. Each isolated organism will be treated with different concentrations of NABC's antibiotics. The results from this will show which antibiotics will work against the bacteria and which concentrations are more effective. This assists the plant in choosing the most effective antibiotic and corresponding dosage rate.

-Genetic ID (AVAILABLE FOR ADDITIONAL CHARGE). Samples are sent to a 3rd party lab for genetic identification. This allows both NABC and the customer to know exactly which organisms are present within the plant. This information will follow the initial report by 7-10 days.

Following are excerpts from a sample report:

This table represents the total bacteria populations found in samples submitted for MBA program.
This table represents susceptibility of theisolated organisms to NABC’s antibiotics: * Control organism

Included in the report is a comprehensive discussion of the findings from mash bacterial testing. Here is an example of some discussion points related to the above graphs:

“Two of the submitted samples demonstrated a bacterial population that could be considered a possible threat to fermentation. Typically, a bacterial population greater than 1x105 cfu/g (>100,000 colony forming units/gram) is considered the threshold for causing significant problems during the fermentation process. The fermentor 2 and 3 samples had bacterial populations greater than 1x107 cfu/g. The ferm 1, beerwell, whole stillage and cook water samples had microbial populations of 103 cfu/g or less, which should not pose a threat to the overall fermentation process.”

“As isolate RB-3 appears to be easily controlled with greater than 0.5ppm of both V50 and V200, treating fermentation with either one of these should remove or reduce this organism to the point where it would no longer be considered a threat. In addition to antibiotic treatment, effective cleaning of the areas such as heat exchangers and mash lines should further reduce the ability of this organism to be a threat to future fermentations.”

All technical advice, services and recommendations by North American Bioproducts Corporation representatives or affiliates are intended for use by persons having skill and know-how in the ethanol productionprocess. Buyer accepts at its own risk and neither North American Bioproducts Corporation nor its representatives or affiliates assume responsibility for results obtained or damages incurred from their use.

Mash Nutrient Analysis Program

This program is provided to give ethanol plants a clear definition of the mineral and nutrient make-up of their mash in relationship to yeast requirements. The testing includes various minerals, several forms of nitrogen testing including FAN, and toxins such as sodium. An ethanol plant gains relevant information in knowing if their mash is deficient in nutrients or high in sodium which will inhibit yeast and fermentation. Anonymous comparative analysis is conducted so that NABC Customers can compare their nutrient profile to other operating ethanol plants. Recommendation: Performed every 60 days and during problem propagation and fermentation.

Following testing, the plant will receive a copy of their individual results.  A composite spreadsheet will also be sent to each participating plant showing anonymous results from all participating plants.  This will allow each plant to compare theri nutrient test results with other plants and see if there are any major deviations.   A plant can utilize this program regularly to detect seasonal differences or determine if there are variations in corn crop.  The composite spreadsheet also includes calculated parameters of nutrient levels needed for yeast health.  This will allow a plant to determine if they have a sufficient amount of nutrients present for good yeast health.  NABC will also review the test results and make suggestions based on the nutrient profile of the mash. 

Mash Yeast Inhibition Testing

This service is provided during times of poor performance to help troubleshoot and give ethanol plants a clear definition of yeast inhibitors within their mash. The testing should be used in conjunction with the mash nutrient testing program. The value to the customer is in knowing if their mash contains compounds that will inhibit yeast and fermentation. Recommendation: Performed every 60 days and during problem propagation and fermentation.

Following testing, the plant will receive a copy of their individual results. NABC will review the test results and make suggestions based on the results and toxicity limits for yeast. This will allow a plant to determine if they have a chemical inhibitor present in the mash.

DDGS Antibiotic Residual Testing

This service is provided to determine and quantify any presence of antibiotic residuals in co-products sold as feed. This program helps the customer by improving quality assurance on their co-product. Reports are designed to potentially assist the ethanol plant in marketing its co-products. Recommendation: Performed every 12 months.

A sample of the co-product is sent in for testing which can detect small levels of active ingredients in antibiotics. NABC will utilize microbiological methods in NABC laboratories for testing and evaluation.

NABC can track and certify antibiotic residuals present in an ethanol plant’s co-product. The testing will demonstrate that the antibiotics passing through the system are either completely denatured or if small amounts are present, this testing will quantify those amounts. The end user of the co-product can be given a copy of the Antibiotic Residual Testing report.

NABC offers testing by LC/MS methods. This test method is state of the art and in line with FDA testing. The producer is ultimately responsible for the suitability and safety of its co-products relevant to their intended use.

If the intended use of the co-product is direct feeding to animals, NABC recommends the use of antimicrobial agents that consist of active ingredients approved by Title 21 CFR 558 for use as a drug in animal feed.