应用沼气池液培养钝顶螺旋藻的初步探讨

A PRELIMINARY ON CULTURING SPIRULINA PLATENSIS USING THE WASTE LIQUID OF BIOGAS GENERATOR

应用广西农村推广的6m^3沼气池产生的废液为氮源,配合海盐,K_2HPO_4,FeSO_4,MnCl_2,NaHCO_3为培养基,在20m^2养藻池中培养螺旋藻成功,平均产量每天7.43g/m^2;经检验,藻体中8种人体必需氨基酸含量很高,每1000克干藻含粗蛋白601.2～634.5克。每生产1000克干藻成本13.3元,且发现这种培养液吸收大气中CO_2的能力很强,池中CO3^(2-)含量逐日上升,不再添加NaHCO_3,螺旋藻仍生长良好;这样可节约大量NaHCO_3,使成本降低。初步试验每1000克掺干藻20克饲料养罗非鱼(Tilapia Niloticas)可提高增重率14.1%。

This paper reports the success of using waste liquid as a nitrogen source in culturing spirulina platensis in a 20m^2 algae basin.The waste liquid,issued from a 6m^3 biogas generator(which is used extensively in the countryside of Guangxi)was mixed with sea-salt,K_2HPO_4,FeSO_4,MnCl_2, NaHCO_3 and water to make up the medium for algoculture.The average output of the dry algae was 7.43 grams per square meter of the basin surface per day,the composition of the spirulina assays was rich in eight kinds of human essential amino acids,and the crude protein was 60.12～63.45% of the dry algae.The cost of the dry algae was 13.3 Yuans per kilogram.Nevertheless it had been found that when the pH of the medium was maintained above 9, the solution could strongly absorb the CO_2 from the atmosphere.Although no further more NaHCO_3 was added into the nutrient solution,the concentration of CO_3^(2-) in the medium increasd slowly day by day,and the algae still grew very well.Thus a large amount of NaHCO_3 could be saved and the costs reduced.2% of the dry spirulina was mixed with the fish forage,and was given to a group of fish(about 1000 Tilapia Niloticas were growing in one net box).After 40 days,the tatal weight of the fish in the experimental group was 14.1% higher than that of the control group.