Large-scale open microalgae cultivation has tremendous potential to make a significant contribution to replacing petroleum-based fuels with biofuels. Open algal cultures are unavoidably inhabited with a diversity of microbes that live on, influence, and shape the fate of these ecosystems. However, there is little understanding of the resilience and stability of the microbial communities in engineered semicontinuous algal systems. To evaluate the dynamics and resilience of the microbial communities in microalgae biofuel cultures, we conducted a longitudinal study on open systems to compare the temporal profiles of the microbiota from two multigenerational algal cohorts, which include one seeded with the microbiota from an in-house culture and the other exogenously seeded with a natural-occurring consortia of bacterial species harvested from the Pacific Ocean. From these month-long, semicontinuous open microalga Nannochloropsis salina cultures, we sequenced a time-series of 46 samples, yielding 8804 operational taxonomic units derived from 9,160,076 high-quality partial 16S rRNA sequences. We provide quantitative evidence that clearly illustrates the development of microbial community is associated with microbiota ancestry. In addition, N. salina growth phases were linked with distinct changes in microbial phylotypes. Alteromonadeles dominated the community in the N. salina exponential phase whereas Alphaproteobacteria and Flavobacteriia were more prevalent in the stationary phase. We also demonstrate that the N. salina-associated microbial community in open cultures is diverse, resilient, and dynamic in response to environmental perturbations. This knowledge has general implications for developing and testing design principles of cultivated algal systems.
The suitability of crude and purified struvite (MgNH4PO4), a major precipitate in wastewater streams, was investigated for renewable replacement of conventional nitrogen and phosphate resources for cultivation of microalgae. Bovine effluent wastewater stone, the source of crude struvite, was characterized for soluble N/P, trace metals, and biochemical components and compared to the purified mineral. Cultivation trials using struvite as a major nutrient source were conducted using two microalgae production strains, Nannochloropsis salina and Phaeodactylum tricornutum, in both lab and outdoor pilot-scale raceways in a variety of seasonal conditions. Both crude and purified struvite-based media were found to result in biomass productivities at least as high as established media formulations (maximum outdoor co-culture yield ~20±4gAFDW/m2/day). Analysis of nutrient uptake by the alga suggest that struvite provides increased nutrient utilization efficiency, and that crude struvite satisfies the trace metals requirement and results in increased pigment productivity for both microalgae strains.
Monitor i ng in f ectio n s in v ect o rs su c h as m osquit o es, s a nd fl i es, tsetse fl i es, a nd ticks to i denti f y hu m a n path o gens m a y s e r v e as a n ear l y w arn i ng det e ction system t o dir e ct loc a l g o v er n ment dise a se pr e v en t i v e m easu r e s . One major hurdle i n de t ection is the abi l i t y to scre e n l arge n u mbers of v e c t ors for h uman patho g ens w i thout t h e u s e of ge n o t y pe - s p ecific m o lecu l ar tec h nique s . N e x t genera t ion s equ e nc i ng (NG S ) pr o v i des a n unbi a sed p latfo r m capab l e of identi f y i ng k n o w n a n d unk n o w n p ath o ge n s circula t ing w i thin a v e ctor p opul a tion, but utili z ing t h is te c h nolo g y i s tim e - con s u ming a n d cos t l y for v ecto r -b o rne disease su r v e illan c e pr o gra m s. T o addr e s s this w e d e v e lop e d cos t -eff e ct i v e Ilumina(r) R NA- S eq l i bra r y p r epara t ion m e thodol o gies i n con j u n ction w i t h an automa t ed c ompu t at i onal a n a l y sis pipel i n e to ch a racter i ze t h e microbial popula t ions c ircula t i n g in Cu l e x m o squit o e s (Cul e x qui n quef a s c iatu s , C ul e x quinq u efasc i atus / pip i ens co m pl e x h y bri d s, and C u l e x ta r salis ) t hroug h out Californ i a. W e assembled 2 0 n o vel a n d w e l l -do c ume n ted a r b o v i ruses repres e nting mem b e rs of B u n y a v ir i da e , F l a v i virid a e, If a virida e , Meson i v i rida e , Nid o v iri d ae, O rtho m y x o virid a e, Pa r v o v iri d ae, Re o virid a e, R h a b d o v i rid a e, T y m o v iri d ae, a s w ell as s e v e r al u n assi g n e d v irus e s . In addit i o n, w e m app e d mRNA s pecies to d i vergent s peci e s of t r y panos o ma a nd pl a s modium eu k a r yotic parasit e s and cha r a c terized t he p r oka r yot i c microb i al c o mposit i on to i d enti f y bacteri a l tran s c r ipts der i v ed from wolba c hia, clo s tridi u m, m y c oplas m a, fusoba c terium and c am p y l o bacter bac t er i al spec i e s . W e utilized the s e mic r obial transcri p tomes pre s e nt in g e ogra p hical l y defined Cul e x po p ul a tions to defi n e spatial and m osqui t o specie s -spec i fic ba r r iers of i n fecti o n. T he v i r ome and microbi o me c o mpos i tion id e ntified in e ach mosqui t o p o ol pr o v i ded suf f icient resolut i on to dete r m i ne both the mosq u ito species and the g e o graphic regi o n in Californ i a w h e re t h e mosqui t o po o l orig i n ated. T his d a ta pr o v i des ins i ght in t o the compl e x i t y of microb i al spec i es cir c ulati n g in med i cal l y i mport a nt Culex mosqui t oes a nd t h eir potent i al im p act o n t he tran s missi o n of v ector-b o rne human / veter i na r y p a t hogens in C a liforn i a.