The contribution of bacteria to algal growth by carbon cycling

Abstract

Algal mass production in open systems is often limited by the availability of inorganic carbon substrate. In this paper, we evaluate how bacterial driven carbon cycling mitigates carbon limitation in open algal culture systems. The contribution of bacteria to carbon cycling was determined by quantifying algae growth with and without supplementation of bacteria. It was found that adding heterotrophic bacteria to an open algal culture dramatically enhanced algae productivity. Increases in algal productivity due to supplementation of bacteria of 4.8 and 3.4 times were observed in two batch tests operating at two different pH values over 7 days. A kinetic model is proposed which describes carbon limited algal growth, and how the limitation could be overcome by bacterial activity to re-mineralize photosynthetic end products.

Agroindustrial Wastewater Treatment with Simultaneous Biodiesel Production in Attached Growth Systems Using a Mixed Microbial Culture

“…The mixed culture used in this study showed higher biomass productivity rates compared to those of related axenic cyanobacterial cultures. It is probable that the added heterotrophic bacteria (contained in wastewaters) enhanced biomass productivity as also observed by Bai et al [70].…”

Algal photosynthetic aeration increases the capacity of bacteria to degrade organics in wastewater

“…Our k L a values for oxygen (1.3-1.7 × 10 −3 s −1 ) fell within the range of those observed in activated sludge tanks operated under different aeration intensities (0.9-2.4 × 10 −3 s −1 ) as measured by Fayolle, Cockx, Gillot, Roustan, and Héduit (2007). These values were also significantly higher than the k L a value (2.8 × 10 −4 s −1 ) observed in the reactor used by Bai et al (2014). Based on diffusivity values for DO and dCO 2 , the theoretical k L a value of CO 2 should be 0.91 times that of oxygen (Grima et al, 2015).…”

Cultivation of Chlorella vulgaris in a Light-Receiving-Plate (LRP)-Enhanced Raceway Pond for Ammonium and Phosphorus Removal from Pretreated Pig Urine

“…(3) Lower inoculation (199.78 vs. 22.32) of the BG11 medium might be another reason for its lower biomass productivity since lower cell density commonly led to photo-inhibition due to the weak shadowing effect between cells [25]. 4Bacteria might also contribute to the robust growth of C. vulgaris in the un-sterilized pig urine [26]. The changes of chlorophyll fluorescence parameters during the treatment of the pretreated pig urine are shown in Figure 4b.…”