PROBLEM TO BE SOLVED: To provide mixed microbial cells which can deodorize only by scattering on droppings in a cattle stall, can neutralize fields, rubble piles, and bad odors in city areas due to the Great East Japan Earthquake, and residential areas and fields damaged with salt, and enables to expect the aging effects, and to provide a neutralized deodorizing-insecticidal agent.SOLUTION: The mixed microbial cells comprise lactic acid bacterium L1 (accession number: FERM AP-22138), lactic acid bacterium L2 (accession number: FERM AP-22139), bacillus B1 (accession number: FERM AP-22136), bacillus B2 (accession number: FERM AP-22137), and yeast Y1 (accession number: FERM AP-22140). An aqueous solution containing the mixed microbial cells is supplied to feed boxes 3 for pigs 4, and scattered or sprayed in pigpens 1.【課題】家畜舎の糞に撒布するだけで消臭し、又、東日本大震災の田畑・瓦礫の山・市街地の悪臭・塩害による住宅地・田畑にも中性化をすることの出来、経年効果が期待できる、混合菌体及び中性化消臭・防虫剤を提供する。【解決手段】乳酸菌L1(受領番号:FERM AP-22138)、乳酸菌L2(受領番号:FERM AP-22139)、桿菌B1(受領番号:FERM AP-22136)、桿菌B2(受領番号:FERM AP-22137)及び酵母Y1(受領番号:FERM AP-22140)を混合してなる混合菌体を含有する水溶液を、豚4のエサ箱3へ供給するとともに、豚舎1内に散布又は噴霧する。【選択図】図1