title: Molecular identification and nanoremediation of microbial contaminants in algal systems using untreated wastewater.
abstract: Wastewater-algal biomass is a promising option to biofuel production. However, microbial contaminants constitute a substantial barrier to algal biofuel yield. A series of algal strains, Nannochloris oculata and Chlorella vulgaris samples (n = 30), were purchased from the University of Texas, and were used for both stock flask cultures and flat-panel vertical bioreactors. A number of media were used for isolation and differentiation of potential contaminants according to laboratory standards (CLSI). Conventional PCR amplification was performed followed by 16S rDNA sequencing to identify isolates at the species level. Nanotherapeutics involving a nanomicellar combination of natural chitosan and zinc oxide (CZNPs) were tested against the microbial lytic groups through Minimum Inhibitory Concentration (MIC) tests and Transmission Electronic Microscopy (TEM). Results indicated the presence of Pseudomonas spp., Bacillus pumilus/ safensis, Cellulosimicrobium cellulans, Micrococcus luteus and Staphylococcus epidermidis strains at a substantial level in the wastewater-fed algal reactors. TEM confirmed the effectiveness of CZNPs on the lytic group while the average MICs (mg/mL) detected for the strains, Pseudomonas spp, Micrococcus luteus, and Bacillus pumilus were 0.417, 3.33, and 1.458, respectively. Conclusively, CZNP antimicrobials proved to be effective as inhibitory agents against currently identified lytic microbial group, did not impact algae cells, and shows promise for in situ interventions.
authors.affiliation: a Department of Cell Biology, Microbiology and Molecular Biology , University of South Florida , Tampa , Florida , USA.
authors.forename: Alya
authors.initials: A
authors.lastname: Limayem
authors.affiliation: a Department of Cell Biology, Microbiology and Molecular Biology , University of South Florida , Tampa , Florida , USA.
authors.forename: Francisco
authors.initials: F
authors.lastname: Gonzalez
authors.affiliation: a Department of Cell Biology, Microbiology and Molecular Biology , University of South Florida , Tampa , Florida , USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Micciche
authors.affiliation: b Department of Integrative Biology , University of South Florida , Tampa , Florida , USA.
authors.forename: Edward
authors.initials: E
authors.lastname: Haller
authors.affiliation: c Water Research Laboratory, Pinellas County Utilities , Largo , Florida , USA.
authors.forename: Bina
authors.initials: B
authors.lastname: Nayak
authors.affiliation: d Department of Internal Medicine , University of South Florida , Tampa , Florida , USA.
authors.forename: Shyam
authors.initials: S
authors.lastname: Mohapatra
mesh_terms: D000069979:Bacillus pumilus / Q000187:drug effects / Q000302:isolation & purification; D056804:Biofuels; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology; D001709:Biotechnology / Q000295:instrumentation* / Q000379:methods; D048271:Chitosan / Q000494:pharmacology*; D048408:Chlorella vulgaris; D000460:Chlorophyta; D008826:Microbial Sensitivity Tests; D016982:Micrococcus luteus / Q000187:drug effects / Q000302:isolation & purification; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods; D011549:Pseudomonas / Q000187:drug effects / Q000302:isolation & purification; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000302:isolation & purification; D062065:Wastewater / Q000382:microbiology*; D015034:Zinc Oxide / Q000494:pharmacology*
chemical_list: D056804:Biofuels; D048271:Chitosan; D062065:Wastewater; D015034:Zinc Oxide
keywords: Pseudomonas; Wastewaters; ZnO; algae; bacterial contaminants; biofuel; chitosan; nanoparticles