Optimizing <i>Bacillus circulans</i> Xue-113168 for biofertilizer production and its effects on crops

Abstract

In this study, Bacillus circulans Xue-113168 biofertilizer was produced through solid state fermentation processes using food waste and feldspar. Results confirmed that solid state fermentation has considerable advantages compared to complex process (solid-state and bio-bleach). The control of pH, temperature, and humidity effectively led to the formation of 2×10⁹ cfu/g spore and dissolution of potassium at a rate of 41.53%. Compound microbial fertilizer (CMF), formulated by humic acid and K₂HPO₄ with biofertilizer, has a quick and durable effect. CMF increases the yield of rapeseeds by 75 to 89%, provides higher vitamin C and reduces nitrate in leaf. Yields of selenium-enriched jujube and jujube increased, respectively, in the CMF compared to the matrix control; rates of anthracnose and rust diseases also decreased. Furthermore, our results showed that CMF improved soil properties, such as organic matter, NPK content from 8.83 to 16.16 kg hm², and reduced chemical fertilizer from 25 to 11%, respectively. For convenient medium, robust process and good effect, CMF is suitable for potassium deficiency and undeveloped arable land resources.

Keywords: compound microbial fertilizer, Bacillus circulans Xue-113168, solid-state fermentation (SSF), process, optimize