title: Microbial community structures in high rate algae ponds for bioconversion of agricultural wastes from livestock industry for feed production.
abstract: Dynamics of seasonal microbial community compositions in algae cultivation ponds are complex. However, there is very limited knowledge on bacterial communities that may play significant roles with algae in the bioconversion of manure nutrients to animal feed. In this study, water samples were collected during winter, spring, summer, and fall from the dairy lagoon effluent (DLE), high rate algae ponds (HRAP) that were fed with diluted DLE, and municipal waste water treatment plant (WWTP) effluent which was included as a comparison system for the analysis of total bacteria, Cyanobacteria, and microalgae communities using MiSeq Illumina sequencing targeting the 16S V4 rDNA region. The main objective was to examine dynamics in microbial community composition in the HRAP used for the production of algal biomass. DNA was extracted from the different sample types using three commercially available DNA extraction kits; MoBio Power water extraction kit, Zymo fungi/bacterial extraction kit, and MP Biomedicals FastDNA SPIN Kit. Permutational analysis of variance (PERMANOVA) using distance matrices on each variable showed significant differences (P=0.001) in beta-diversity based on sample source. Environmental variables such as hydraulic retention time (HRT; P<0.031), total N (P<0.002), total inorganic N (P<0.002), total P (P<0.002), alkalinity (P<0.002), pH (P<0.022), total suspended solid (TSS; P<0.003), and volatile suspended solids (VSS; P<0.002) significantly affected microbial communities in DLE, HRAP, and WWTP. Of the operational taxonomic units (OTUs) identified to phyla level, the dominant classes of bacteria identified were: Cyanobacteria, Alpha-, Beta-, Gamma-, Epsilon-, and Delta-proteobacteria, Bacteroidetes, Firmicutes, and Planctomycetes. Our data suggest that microbial communities were significantly affected in HRAP by different environmental variables, and care must be taken in extraction procedures when evaluating specific groups of microbial communities for specific functions.
authors.affiliation: US Salinity Laboratory, USDA-ARS, 450 W. Big Springs Rd., Riverside, CA 92507, USA. Electronic address: Mark.Ibekwe@ars.usda.gov.
authors.forename: A
authors.initials: A
authors.lastname: Mark Ibekwe
authors.affiliation: Animal and Veterinary Sciences Department, California State Polytechnic University, Pomona, CA 91768, USA.
authors.forename: Shelton E
authors.initials: SE
authors.lastname: Murinda
authors.affiliation: Biological Sciences Department, California State Polytechnic University, Pomona, CA 91768, USA.
authors.forename: Marcia A
authors.initials: MA
authors.lastname: Murry
authors.affiliation: BioResource and Agricultural Engineering Department, College of Agriculture, California Polytechnic State University, San Luis Obispo, CA, USA.
authors.forename: Gregory
authors.initials: G
authors.lastname: Schwartz
authors.affiliation: Civil and Environmental Engineering Department, College of Engineering, California Polytechnic State University, San Luis Obispo, CA, USA.
authors.forename: Trygve
authors.initials: T
authors.lastname: Lundquist
mesh_terms: D000818:Animals; D001419:Bacteria / Q000254:growth & development*; D058751:Livestock; D008372:Manure; D058086:Microalgae / Q000254:growth & development*; D061005:Ponds / Q000382:microbiology*; D012621:Seasons; D014865:Waste Disposal, Fluid; D062065:Wastewater
chemical_list: D008372:Manure; D062065:Wastewater
keywords: Algae production; Cyanobacteria; Dairy lagoon effluent; High rate algae ponds; Microalgae; Microbial community