Abstract: In the way of liquid fermentation, the yeast was inoculated into soybean meal, and the fermentation at different temperatures on shake. After different fermentation time, the fermentation liquid was used to culture chlorella directly and boiled. The growth trend of chlorella was determined by measuring the A₆₈₀ of culture fluid, using BG11 culture liquid as the control group, and some parameters affecting the water quality in the culture liquid were measured. the results showed that the ferment filtrate at 29 ℃ combined with BG11 culture medium could promote the growth of Chlorella most effectively, next was fermentation product at 28 ℃, A₆₈₀ was 1.532 and 1.463 respectively after culturing for 9 days, and the worst culture effect was using BG11 culture medium alone （P<0.01）; the effect of chlorella culture with bacteria removal was better than that without bacteria removal （P<0.01）; the best liquid fermentation temperature with soybean meal by yeast was 28 ℃ and the best fermentation time was 7 days; the ammonia nitrogen, total nitrogen and nitrite in the fermentation liquid of soybean meal could be eliminated basically after culturing chlorella, but the concentration of total nitrogen and nitrite in BG11 culture liquid maintained a high level; the consumption of soybean meal after fermentation was consistent with the production of chlorella; after culturing chlorella for 7 days, the parameters related to water pollution reached class II level. the ferment of soybean meal by yeast was suitable for rapid cultivation of feed grade or food grade Chlorella, and could be used in aquaculture directly without any treatment.

Key words: chlorella culture, yeast, fermentation of soybean meal