Understanding the biochemical characteristics of struvite bio-mineralising microorganisms and their future in nutrient recovery

Abstract

The biochemical properties of selected microorganisms (Bacillus pumilus, Brevibacterium antiquum, Myxococcus xanthus, Halobacterium salinarum and Idiomarina loihiensis), known for their ability to produce struvite through biomineralisation, were investigated. All five microorganisms grew at mesophilic temperature ranges (22-34°C), produced urease (except I. loihiensis) and used bovine serum albumin as a carbon source. I. loihiensis was characterised as a facultative anaerobe able to use O 2 and NO 3 as an electron acceptor. A growth rate of 0.15 1/h was estimated for I. loihiensis at pH 8.0 and NaCl 3.5% w/v. The growth rates for the other

Understanding the mechanisms of biological struvite biomineralisation

“…2 d) was observed for all the five investigated microbial cultures. The sizes of such small particles were the same order of magnitude than those of the investigated microbial cells' (Leng et al, 2020). An evolution of crystal morphology from cell cluster to bulk crystal with smooth surface was also observed (Fig.…”

“…SP The major carbon source in B41 media was yeast extract, that is rich in protein (50-75%) and carbohydrates (4-13%) (EURASYP, 2014). Protein was reported as the preferred carbon source for the selected microorganisms (Leng et al, 2020). After 24 h incubation, the media still contained significant amounts of SCOD and the cultures reached stationary phase of growth (Fig.…”

“…There was no significant loss of Mg and P by extracellular materials such as eDNA or polyphosphate during microbial growth and activity. Furthermore, a constant NH4-N concentration of 1 mM within cells was assumed; as well as equal distribution of PO4-P and Mg 2+ ions in the cytoplasm; a constant degree of intracellular SIstruvite during the incubation period; and intracellular neutral pH of 7 for H. salinarum, M. xanthus, B. antiquum and B. pumilus and mild alkaline pH of 8 for I. loihiensis (Leng et al, 2020). The mass balance of NH4-N cannot be completed in this study due to loss of nitrogen caused by volatilization of ammonia from crystalline frameworks of bio-struvite during air-drying.…”

“…The microbial growth hence created a mild alkaline environment where the Mg 2+ was no longer soluble and integrated with PO4-P and NH4-N to precipitate as bio-struvite (Smirnov et al, 2005). The microorganisms investigated in this study were known to be capable of using proteins/amino acids as a carbon source (Leng et al, 2020). Thus, the yeast extract applied in this study was not only providing microbial growth with a carbon source but also was used as the main source for NH4-N production.…”

Recovery of Phosphorus from Waste Water Profiting from Biological Nitrogen Treatment: Upstream, Concomitant or Downstream Precipitation Alternatives

“…Candidatus Accumulibacter phosphatis, which is commonly found in EBPR systems [175], has also been found in granular PNA systems and identified as potentially responsible for inducing HAP precipitation [176]. Biologically induced MAP production from anaerobic sludge dewatering centrates has also been demonstrated as feasible in preliminary incubation experiments using specifically selected microbial strains (e.g., Bacillus pumilus, Brevibacterium antiquum, Myxococcus xanthus, Halobacterium salinarum, and Idiomarina loihiensis), opening a completely new route for P recovery via biomineralisation [166,177,178]. On this line, biologically mediated MAP (and other MgP together with calcium carbonate) precipitation was also reported in open, mixed-culture, biofilm bioreactors treating low-strength domestic waste water, while potentially responsible microorganisms were isolated for further characterisation (mostly heterotrophic bacteria growing aerobically) [179,180].…”