Study On Solid Cultivation Of Nostoc Commune

Nostoc is a genus of filamentous nitrogen-fixing cyanobacteria and some kinds have very high economic and application value. As the influence of industrialization and urbanization,the wild habitat of Nostoc is under great threatened and its habitat range is narrowed sharply. Especially the habitats of N. commune, N. sphaeroides and N. flagelliforme are severely damaged, moreover, their production are serious shortage. However, in addition to factory-scale production of N. sphaeroides, the artificial cultivation of N. commune and N. flagelliforme have not been breakthrough.In this paper, N. commune was obtained from Shenchi in Shanxi Province. Three aspects were stduied in this paper, including development and life history, phycobiliprotein and artificial solid cultivation.The development of N. commune has experienced a series of complex physical and chemical processes. The complete life history was divided into four stages:hormogonia stage, microcolony stage, macrocolony stage, forming stage. In all the four stages, hormogonia stage and microcolony stage are development stage in total Nostoc genus. Morphology of N. commune depend on macrocolony stage to forming stage. Some stages’development time would prolong in different habitats and some may even disappear.Four different methods, soil cultivation, solid agar cultivation, alginate-immobilized cultivation, solid-liquid mixed cultivation, were used to culture N. commune. The results showed that solid-liquid mixed cultivation was the best way. Solid agar cultivation was not suit for culture of N. commune. Alginate-immobilized cultivation was suit for liquid culture, because its growing speed was very fast and other algae’s influence was less. Using HB-4culture medium to soil cultivation, the best result was171.8%in a week. But this method could not culture for long time. Soil cultivation condition was similar with wild habitat, however, the wet-dry alternating was very hard to control.Six different strains of N. commune’s water sorption value and phycobiliprotein content value were determined. The result showed that different strains had different water sorption value, but the values were all beyond80%. Shenchi strain water sorption value was best (90.63%), Yulin strain’s was least (80%). Determination of phycobiliprotein content showed that Inner Mongolia strain’s PC, APC, PE content were all highest among six strains.Yulin strain was on the contrary.