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Understanding Bacteria & Enzymes

Originally written by one of Aquatic Biologists, Inc staff biologists for publication in Pond Keeper Magazine (now Pond & Garden Lifestyle).

Bacteria are the base for the animal food chain within a pond or lake. Bacteria consume (decompose) waste products and assimilate nutrients by converting this material to other bacteria through the process of growing, reproducing, and multiplying. Bacteria then become the food source for other aquatic organisms such as zoo-flagellates, ciliates, and rotifers, which in turn become food for fish, insects, invertebrates, and other organisms. These living organisms compete for the nutrients (nitrogen and phosphorus) necessary for the growth of algae. Depending on the type of product and the species in it, bacteria can reduce organic sediment (muck) from the lake bottom, improve water clarity, reduce the amount of nitrogen and phosphorus available for algae growth, and aid in the improvement of overall water quality.

Life on earth, as we know it, would not exist without enzymes, just as life would not exist without oxygen or water. Enzymes are organic proteins made from amino acids. An enzyme is formed by stringing together 100 or even 1,000 amino acids in a very specific and unique order. The chain of amino acids then folds into a unique shape that allows the enzyme to act as a catalyst to carry out specific chemical reactions.

Although enzymes catalyze (enhance) the chemical reaction by breaking molecules apart and putting molecules together. Enzymes are not consumed in the process. Enzymes perform the vital function of controlling the metabolic processes in which nutrients are converted into energy and fresh cell material. In nature, enzymes control the build-up and decomposition of essential matter in vegetable and animal organisms.

The efficiency of any enzyme or bacteria depends on the amount of wastes available, the abundance of dissolved oxygen accessible to the organisms, water chemistry (ex. pH), and the type or strains of bacteria present to do the job. In eutrophic (aging) ponds and lakes where aquatic plants and algae are a problem, there is normally an abundance of organic wastes.

Bioaugmentation product prices vary depending on quality, concentration, dilution, and product effectiveness. It is important to carefully determine the total amount of product needed for season-long maintenance.

After reviewing what bacteria and enzymes are, it is time to choose what product line to best fit your needs. Protect yourself, by investing your time researching the product you are contemplating purchasing before you invest your money. Below, you will find several things to look for when choosing your bioaugmentation products.

1) It is important to look for bacteria that are cultured and grown within a "Food Grade Plant" that is inspected regularly by the Food and Drug Administration (FDA). In this way, you are ascertained that your product is free of contamination from coliforms and/or other potentially harmful bacteria.

2) State - of- the art manufacturing techniques should be used in the manufacturing of your product that encompasses Good Manufacturing Practices (GMP). The manufacturing process is required by the FDA to meet all GRAS ("generally recognized as safe") components during production. (GRAS is a substance that is determined to be safe based on proven science, or has a long history of safe usage in food.)

3) The product line you use should have been rigorously tested for human safety, biodegradability, and aquatic safety.

4) How many bacteria are present in each gram of product? Generally, the higher this number the better the product will perform.

5) Look for bacterial products with several different strains within them. This holistic approach ensures the right bacteria strains are present for almost any application. The product morphology should contain bacillus bacteria for normal summer applications. Select strains of pseudomonas bacteria should also be in the product make-up when water temperatures are above 80° F.

6) The bacterial product should contain a high-quality nutrient package. The bacteria will feed off these nutrients until they reach the organic food sources available within the water column or on the lake or pond bottom (otherwise they may die and become ineffective).

7) Heterotrophic, chemolithotrophic, and autotrophic are terms used to describe certain bacteria which are normally used in bioaugmentation products. It is generally wise to have all three bacteria types present within your bacterial bioaugmentation products.Look to see if the product is laboratory tested for each lot number to ensure the quantity of bacteria present within the final product meets or exceeds the advertised concentration levels.

• Heterotrophic bacteria are saprobes (feed on dead organic material). Heterotrophic bacteria regularly consume phosphorus, organic carbon (carbohydrates, lipids, and proteins), and nitrogen present within the dead organic mass that would otherwise become organic sediment. (Phosphorus, carbon, and nitrogen are the major components of organic sediment, which accumulates on the bottom of lakes and ponds).

• Chemolithotrophic bacteria oxidize ammonia (NH3) to nitrite (NO2) they then convert the nitrite to nitrate (NO3) and finally convert the nitrate into completely non-toxic nitrogen gas. Chemolithotrophic bacteria consume large quantities of phosphate during this conversion process making the phosphate unavailable to other organisms such as algae.

• Autotrophic bacteria have the unique ability to use carbon dioxide (CO2) (with energy from the sun) as their sole food source while utilizing nitrogen only for regeneration. (In other words, they can live, and many times thrive when there is little or no dissolved oxygen present.) The autotrophics include such species as nitrosomonas and nitrobacter bacteria.

8) Facultative bacteria have the ability to use all energy sources (oxygen, nitrogen, and sulfur) within a lake or pond. The more energy (ATP) (Adenosine triphosphate) the bacteria can obtain, the better they can function and thrive within a waterbody. (ATP are considered by biologists to be the energy currency of life. ATP are the high-energy molecules that store the energy we need to do just about everything we do.) Facultative bacteria will always obtain the best energy source available, but can and will function in an oxygen-deficient environment.

9) Water temperature directly affects the potential bacteria have to propagate and thrive within a lake or pond. It is important to confirm with the manufacturer water temperature requirements necessary for best results, along with the rate at which propagation occurs. Water temperature requirements should be clearly stated on the product label.

10) Obtain documentation from the manufacture or distributor(s), regarding the rates bacteria perform under varying water temperature degrees (i.e. 40°, 50°, 60°, etc.)

The Eight Major Enzyme Groups

Enzymes are available in a wide range of concentrations. What works for a 12' diameter garden pond will not work for a 10-acre lake and vise versa. As a general rule of thumb the smaller the pond, the less concentrated the enzyme product should be.

Amylase Breaks down Sugars
Cellulase Breaks Down Plant Materials
Keratinase Breaks Down Plant Materials
Lifinase Breaks Down Plant Materials
Lipase Breaks Down Fats & Oils
Pectinase Breaks Down Plant Materials & Sugars
Protease Breaks Down Proteins
Xylanase Breaks Down Plant Materials


A well-formulated and effective enzyme product should contain thousands of enzyme types from eight major groups. These enzyme groups aid in the digestion of leaf litter, dead algae cells, grass clippings, dead plant matter, goose manure, and other organic materials. Enzymes may be used alone or in combination with augmented (added) microbial bacteria populations. When used in a combination, enzymes dramatically encourage both the naturally occurring and augmented bacterial populations to flourish and digest organic materials.

Bacteria and enzymes will normally work more effectively within a friendly lake or pond environment. There are seven requirements listed below to have when using bacteria products for success. Without these requirements present, you may have little or no results, no matter what concentration of bacteria you apply.

1) There must be nutrients available immediately after application to provide a food source. If you are adding bacteria to the pond surface only, results will be minimal at best.

2) It is best to apply in a friendly environment where dissolved oxygen levels are maintained at the sediment layer.

3) It is best to use bacteria products and concentrations that have the correct species & population to accomplish your lake or pond objectives.

4) Water temperature should be warm enough to support the propagation of new bacteria (this should be stated on the product label).

5) Know the total phosphorus level of the water you are using the product in when your goals are directed at algae management. Phosphorus levels may be tested relatively inexpensively at many labs throughout the country.

6) Know the composition of the bottom sediment when your goals are directed at sediment reduction by performing a percent organics test. This test will provide you with the total percentage of organic material in the bottom sediment to enable you to determine if bacteria and enzymes are viable and cost-effective tools in any one lake or pond. Generally, the higher the percentage of organic material available in the sediment layer the better the bacteria and enzyme products will work. Remember, you cannot expect bacteria and enzyme products to work effectively in an inorganic environment.

7) Make sure that the purpose for adding bacteria and enzymes is defined. As an example, if the purpose for adding bacteria is to reduce organic bottom sediments then a sampling protocol should be implemented to determine how effective the bioaugmentation products are.

All bioaugmentation products work best when a regular weekly maintenance schedule is followed through the spring, summer, and fall. One to two week maintenance is generally recommended with the majority of products. The reason for this regular maintenance is that within a two weeks, most bacteria will have "degenerated" into a "species" less apt to regenerate quickly and into one that is essentially "taking the easy way out". In other words, all augmented bacteria "interbreed" producing a bacterial strain that expends the least amount of energy required for survival.

Finally, bioaugmentation can be complex, but with a little research and some simple water tests, the right bioaugmentation products can greatly improve the overall health and management of your lake or pond.