MECHANISM OF AN EARLY LYSIS BY FATTY-ACIDS FROM AXENIC PHORMIDIUM TENUE (MUSTY ODOR-PRODUCING CYANOBACTERIUM) AND ITS GROWTH PROLONGATION BY BACTERIA

We hale previously demonstrated that bacteria-containing Phormidium te nue, a cyanobacterium which produces musty odor 2-methylisoborneol, gr ew beyond 8 weeks, whereas axenic alga perished suddenly between the 3 rd week and the 4th week while being cultured in the laboratory, This mechanism was investigated, It is assumed that when algal cells grow b eyond a certain level, the supply of CO2 becomes inadequate and result s in the rapid lysis of axenic alga. At that time, inhibitory substanc es liberated from algal cells kill the surviving alga, Since the proce ss occurs continuously, this alga is finally annihilated. On the other hand, since inhibitory substances are metabolized or degraded by bact eria coexistent with alga, bacteria-containing P. tenue maintains grow th for a long time. The growth-inhibitory substance was found to be un saturated free fatty acids.