Abstract

Project Title: Isolation of Corn Stalks Degrading Microbes from Soil
Student: Yuxiao Tan
Mentor: Dr. Laura Tuhela-Reuning

A large quantity of corn is cultivated every year resulting in the production corn stalk waste. Current solutions for dealing with corn stalk waste include transforming corn stalks into animal feed or incineration. However, many bacteria and fungi can utilize cellulose, the main component of corn stalks, as a source of carbon and energy resulting in the production of humic acid, an absorbable fertilizer for crops. Therefore, bacteria and fungi capable of metabolizing cellulose as a carbon source have the potential to function as an efficient bio-fertilizer.

Cellulose-degrading bacteria and fungi were isolated from cornfield soil and cultured on a self-designed medium, which contained 1% corn stalks as the only source of organic carbon, 1.5% agar, 1g/L (NH₄)SO₄, 1g/L KH₂PO₄, O.1g/L MgSO₄ • 7H₂O, 0.01g/L NaCl, 0.01g/L CaCl₂, 0.003g/L FeCl₃, and 0.015g/L MnSO₄ • 7H₂O. Three strains of corn stalk degrading bacteria and six strains of corn stalk degrading fungi were isolated. From the results of eight control groups, corn stalks were shown to be the sole carbon source for target microbes, and the degrading of corn stalks was not caused by the colliding with soil particles during incubation. Subsequently, optimum growing conditions, such as temperature, pH, and nutrients condition will be determined for the isolated bacteria and fungi, and biochemical tests will be performed to develop a combination of microbes to produce a novel bio-fertilizer.