title: Enhancement of Chlorella vulgaris growth and bioremediation ability of aquarium wastewater using diazotrophs.
abstract: Treatment of aquarium wastewater represents an important process to clean and recycle wastewater to be safely returned to the environment, used for cultivation or to minimize the multiple renewal of water. Chlorella vulgaris was an important freshwater microalgae which used in wastewater treatment, and increasing its potential of treatment can be achieved with existence of N2-fixing bacteria. Co-culturing of Chlorella vulgaris with the diazotrophs, Azospirillum brasilense or Azotobacter chroococcum in three different media; aquarium wastewater (AWW), sterile enriched natural aquarium wastewater (GPM) and synthetic wastewater media (SWW) were studied. Biomass yield of the microalgae was estimated by determination of chlorophylls (a and b), total carotenoid and the dry weight of C. vulgaris. Also determination of ammonia, nitrite, phosphate and nitrate in the culture were done. The presence of diazotrophs significantly increased the biomass of C. vulgaris by increasing its microalgae pigments (chlorophylls a and b, and total carotenoids). The highest pigments percentage was reported due to addition of A. brasilense to C. vulgaris (18.3-133.5%) compared to A. chroococcum (23.9-56.9%). As well as increased dry weight from 12 to 50%. There was also improved removal of nitrate, nitrite, ammonia and phosphate; where, the highest removal percentage was reported due to addition of A. chroococcum to C. vulgaris (0.0-52%) compared to A. brasilense (0.6-16.4%). A. brasilense and A. chroococcum can support C. vulgaris biomass production and bioremediation activity in the aquarium to minimize the periodical water renewal.
authors.affiliation: Department of Microbiology, Aswan Research Station, National Institute of Oceanography and Fisheries, Egypt.
authors.forename: Sayeda Mohammed
authors.initials: SM
authors.lastname: Ali
authors.forename: Hoda Shafeek
authors.initials: HS
authors.lastname: Nasr
authors.forename: Wafaa Tawfik
authors.initials: WT
authors.lastname: Abbas
mesh_terms: D015806:Azospirillum brasilense / Q000378:metabolism*; D001673:Biodegradation, Environmental; D018533:Biomass; D048408:Chlorella vulgaris / Q000254:growth & development* / Q000378:metabolism; D062065:Wastewater; D014873:Water Pollutants / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D062065:Wastewater; D014873:Water Pollutants