PRODUCTION OF RAW MATERIALS FROM CYANOBACTERIA FOR BIOFERTILIZERS INDUSTRY

Abstract

El-Khadra lake was physically, chemically and microbiologically evaluated at surface layer and depths of 30 cm, 1 meter and sediment water in September 2011 and February 2012. Physico-chemical analysis of lake water samples revealed the alkaline nature of the lake with high concentrations of Na+ and Cl- ions at all depths in both seasons. Na+ ion concentrations ranged from 27.124 to 30.569 g/l in September samples and from 9.235 to 9.734 g/l in February samples, while Cl- ions ranged from 15.606 to 21.275 g/l in September samples and from 10.686 to 11.928 g/l in February samples. Higher bacterial counts were detected in sediment water samples in both seasons (990 and 910 cfu/ml in September and February samples, respectively). Fungal counts were higher in September samples at 1meter depth (290 cfu/ml), while in February samples, the higher fungal counts were recorded at 30 cm (110 cfu/ml). Total and feacal coliforms scored few numbers in both seasons. Many cyanobacterial species besides some algae were detected in the lake including Chlorella, circular diatom (Puncticulata sp.), Oscillatoria, Spirulina, Nostoc and Anabaena spp. Among those, three representative species were isolated and identified by TEM and molecular techniques as Spirulina sp., Oscillatoria sp and Anabaena sp. Their intra- and extra-cellular extracts showed no considerable influence on brine shrimp eggs and mice survival. However, they showed also considerable antimicrobial activities against five microorganisms i.e., E.coli, S. aureus, P. aeroginosa, B. subtilis and A. niger. Chemical analysis of cyanobacterial isolates showed that Spirulina had the highest protein percentage and amino acids content in addition to appreciable amounts of phytohormones. Oscillatoria recorded higher content of photosynthetic pigments including phycobiliproteins. On the other hand, a pot experiment was performed to examine the effect of foliar application of cyanobacterial cultures, filtrates and dried biomasses that were dissolved either in water or in culture filtrate on pepper seedlings. Spirulina-treated plants showed more enhanced plant growth than control and other treated plants. Data also indicated that plants treated with Spirulina culture and filtrate showed some wilting symptoms. Therefore, a confirmation pot experiment was performed to examine the effect of different concentrations of Spirulina culture filtrate on the vegetable plant. The dilution ratio of 1:2 (filtrate: water) showed the most enhanced growth parameters compared with control plants. Key words: El-Khadra Lake, cyanobacteria, Spirulina, Oscillatoria, Anabaena, antimicrobial activity, foliar application, pepper, biofertilization.