PEMANFAATAN LIMBAH CAIR PERTANIAN SEBAGAI MEDIA PERBANYAKAN Bacillus Sp. DB 12

The purpose of the study was to determine the appropriate formulation concentration and to maintain the population density of Bacillus sp. DB 12 on tofu liquid waste media and rice washing water for 8 weeks. This research was carried out in March 2021 until it was completed at the Disease Laboratory, Department of Plant Pests and Diseases, Agrotechnology Study Program, Faculty of Agriculture, Tadulako University, Palu. This study used a completely randomized design (RAL) with 6 treatments, namely L0: 100 ml tofu liquid waste, L1: 80 ml tofu liquid waste + 20 ml rice washing water waste, L2: 60 ml tofu liquid waste + 40 ml rice water, L3 : 40 ml tofu water + 60 ml rice water, L4: 20 ml tofu water + 80 ml rice water, L5: 100 ml rice washing water waste. Each treatment was repeated 5 times to produce 30 experimental units. Observation variables include the characteristics of the colonies of Bacillus sp. DB 12 and the population density of Bacillus sp. DB 12. The first stage data were analyzed simply by comparing the growth pattern of Bacillus sp. while for the second stage, it was further tested with 5% BNJ. The results showed that treatment L0: concentration of 100 ml tofu liquid waste was the best waste medium for the propagation of Bacillus sp. with an average population density of 1.092% at week 0 and 1.690% at week 8 according to the 5% BNJ. Differences in organic matter, nutrient content, pH and storage time at each concentration affect the growth of the bacterial population.
Keywords: Growth, Bacillus sp., storage, Liquid Waste.