Beneficial Microbes | Pathogen Control

Beneficial Microbes in Hydroponics

One reason soil-less cultures were originally developed was to control soil borne diseases. Soil-less cultures provide several advantages for growers such as greater production of crops, reduced energy consumption, better control of growth and independence of soil quality. But root diseases still occur frequently in hydroponics and disease outbreaks are sometimes greater than in soil (Stanghellini and Rasmussen, 1994). Pythium and Phytophthora sp. are particularly well adapted to aquatic environments. Their growth in soil-less substrates is favored by the recirculation of the nutrient solution. These pathogenic microorganisms are usually controlled by disinfection methods but such methods are only effective as a preventive measure. More recently there has been an increase in investigations on proventing pathogens by the addition of antagonistic microorganisms.  For example the study and subsequent report Pathogenic and beneficial microorganisms in soilless cultures is a good example of this new interest in horticultural sciences.

However much of the new research has yet to go deeply into the hydro-oganics where soil is a basic structure placed solidly in the system. The OST hydro-organic system’s inherent soil structure inoculates the water with elementary beneficial microorganisms constantly. The water, biofilm and substrate, with their established community, acts as a buffer against pathogen intrusion. Refer to the report Microbial ecosystem constructed in water for organic hydroponics pdf. In this report by NARO researcher Makoto Shinohara,  demonstrates how the susceptibility to bacterial wilt disease of tomato was examined by inoculation of the culture solution with Ralstonia solanacearum. His study shows that more than half of the plants grown with chemical fertilizer died from bacterial wilt disease, while there were no wilted tomato plants among those grown hydro-organically.

However much of the new research has yet to go deeply into the hydro-oganics where soil is a basic structure placed solidly in the system. The OST hydro-organic system’s inherent soil inoculates the water with elementary beneficial microorganisms constantly. The water, biofilm and substrate, with their established community, acts as a buffer against pathogen intrusion.

An established community of beneficial bacterias and fungus compete for room. They exude hydrolytic enzymes and antibiotics to suppress the growth of non communal pathogens. There is a synergism between the antibiotics and hydrolytic enzymes produced by bacteria. Firstly, the enzymes degrade the cell wall of the pathogen, and secondly, this enables the toxin to act more efficiently against the pathogen by gaining access at an intracellular level.

Beneficial Microbes | Nitrification

Nitrification is the aerobic conversion of ammonia into nitrates. The bacteria responsible for this process form a biofilm on all solid surfaces throughout the system that are in constant contact with the water. The submerged roots, substrate and tank walls combined have a large surface area, so that single floating bacteria can accumulate and begin to form their natural environment of a biofilm. Care for these bacterial colonies is important not only to keep pathogens in check, but also to regulate the full assimilation of ammonia and nitrite for effective Hydro-Organic Nitrification.

Nitrification is one of the most important functions in the OTS Hydro-Organic system as it reduces the toxicity of the organic compounds in the water and allows the resulting nitrate compounds to be used by the plants for nourishment. Organic compounds can be converted into other nitrogenous compounds through healthy populations of Nitrosomonas bacteria that convert ammonia into nitrites, and Nitrobacter bacteria that convert nitrites into nitrates, which is the preferred nitrogen for more than 90% of all plant species.