Isolation and application of a wild strain photosynthetic bacterium to environmental waste management

Abstract

ABSTRACT:A new photosynthetic bacterium isolate was morphologically identified as a non-motile rod-shape gram-negative bacterium. It produced a dark red culture under phototrophic condition, reproduced by budding and formed a lamellar intracytoplasmic membrane system parallel to cytoplasmic membrane, which contained bacteriochlorophyll a and caratenoids. It's physiological and nutrient requirement tests gave indication that the isolate thrived and multiplied in varied environmental conditions. It was consequently named Z08 and identified as Rhodobacter sphaeroides by 16SrDNA. Adaptation of Z08 to biodegradation of two environmentally concerned wastewaters, i.e. soybean and pharmaceutical wastewaters, attested its potential in wastewater bioremediation. Z08 adaptation in a suspended batch photobioreactor treating pharmaceutical wastewater at 3500lx radiation recorded best result after wastewater dilution of 1:4 with concomitant chemical oxygen demand reduction, biomass yield and specific growth of 50 %, 780 mg/L and 0.015/h, respectively at the lowest hydraulic retention time of three days. Furthermore, gas chromatography mass spectra analyses of treated and raw pharmaceutical wastewater indicated that high molecular weight recalcitrant compounds found in the pharmaceutical wastewater were transformed to less toxic and acceptable lower molecular weight substances through biodegradation. Whilst Z08 treatment of soybean wastewater under natural light intensity radiation recorded 80 % reduction, 1540 mg/L and 0.025/h for chemical oxygen demand, biomass and specific growth rate respectively regardless of the food to microorganism ratio. This preliminary investigation showed that isolate Z08 has some toxic tolerance level which could detoxify refractory substances with great potential for cell protein recovery in high organic strength wastewater. Therefore, strain Z08 could be employed in biodegradation of contaminated wastewater streams.

Simultaneous nutrient and carbon removal from azo dye wastewater using a photorotating biological contactor reactor

“…Based on the high TN removal efficiencies and high protein content of biofilm in the PRBC, we hypothesized that N assimilation into biomass was likely the main TN removal mechanism present in the photosynthetic biofilm. Although the protein content was obtained in mixed culture, it was comparable with protein contents of pure cultured APB strains, which were reported to be 67.6% as crude protein in Rhodocyclus gelatinosus , 65.2%, as crude protein in Rhodopseudomonas sp., and 42% as crude protein in Rhodobacter sphaeroides …”

“…Although the protein content was obtained in mixed culture, it was comparable with protein contents of pure cultured APB strains, which were reported to be 67.6% as crude protein in Rhodocyclus gelatinosus, 21 65.2%, as crude protein in Rhodopseudomonas sp., 22 and 42% as crude protein in Rhodobacter sphaeroides. 23 In addition, extracellular and intracellular accumulation of P was 2.4% as TP in the biofilm of the PRBC. This value was slightly lower than that reported for pure cultured APB strains.…”

Nutrient Recovery From Cyanobacteria Biomasses Using Purple Nonsulfur Bacterium Rhodopseudomonas palustris

“…PNSB, an eco-friendly and cheap tool for bioremediation, has high efficiency in wastewater treatment in the reduction of N, P, and COD [39]. By 1:4 dilutions, reduction of 50% in COD was observed by applying Rhodobacter sphaeroides Z08 during pharmaceutical wastewater treatment with biomass yield of 780 mg/L and specific growth of 0.015 h -1 [40].…”

Characterization of a newly isolated Rubrivivax benzoatilyticus PS-5 with self-flocculation property and optimization pathway for 5-aminolevulinic acid production

“…The Rhodospirillum medium (RM) used for enrichment and isolation contained (gl -1 ): 4, D,L malate; 0.1, yeast extract; 0.12, MgSO 4 .7H 2 O; 0.076, CaCl 2 .2H 2 O; 0.02, Na 2 EDTA; 0.59, KH 2 PO 4 ; 0.39, K 2 HPO 4 ; 0.0065, FeSO 4 .7H 2 O; 0.0003, MnCl 2 .4H 2 O; 0.01, ZnSO 4 .7H 2 O; 0.02, CoSO 4 .7H 2 O; 0.03, H 3 BO 3 ; 0.003, Na MoO 4 .2H 2 O; 0.001, CuSO 4 .5H 2 O (Madukasi et al, 2011).…”