A versatile method for preparation of hydrated microbial–latex biocatalytic coatings for gas absorption and gas evolution

Abstract

We describe a latex wet coalescence method for gas-phase immobilization of microorganisms on paper which does not require drying for adhesion. This method reduces drying stresses to the microbes. It is applicable for microorganisms that do not tolerate desiccation stress during latex drying even in the presence of carbohydrates. Small surface area, 10-65 μm thick coatings were generated on chromatography paper strips and placed in the head-space of vertical sealed tubes containing liquid to hydrate the paper. These gas-phase microbial coatings hydrated by liquid in the paper pore space demonstrated absorption or evolution of H₂, CO, CO₂ or O₂. The microbial products produced, ethanol and acetate, diffuse into the hydrated paper pores and accumulate in the liquid at the bottom of the tube. The paper provides hydration to the back side of the coating and also separates the biocatalyst from the products. Coating reactivity was demonstrated for Chlamydomonas reinhardtii CC124, which consumed CO₂ and produced 10.2 ± 0.2 mmol O₂ m⁻² h⁻¹, Rhodopseudomonas palustris CGA009, which consumed acetate and produced 0.47 ± 0.04 mmol H₂ m⁻² h⁻¹, Clostridium ljungdahlii OTA1, which consumed 6 mmol CO m⁻² h⁻¹, and Synechococcus sp. PCC7002, which consumed CO₂ and produced 5.00 ± 0.25 mmol O₂ m⁻² h⁻¹. Coating thickness and microstructure were related to microbe size as determined by digital micrometry, profilometry, and confocal microscopy. The immobilization of different microorganisms in thin adhesive films in the gas phase demonstrates the utility of this method for evaluating genetically optimized microorganisms for gas absorption and gas evolution.

Agriculture-independent, sustainable, fail-safe and efficient food production by autotrophic single-cell protein

“…Coated Paper Array Contactor are composed of paper matrices on which convective assembly of living cells and adhesive latex particles forms colloid-latex biocomposite adhesive coatings [96,97,98]. While the paper provides mechanical stability, hydration and diffusion of products, 1 st stage bacteria are entrapped at high density in the microporous latex film which prevents biomass outgrowth while still permitting a reasonable exchange of substrate gases and acetate.…”

Microbial Paper: Cellulose Fiber-based Photo-Absorber Producing Hydrogen Gas from Acetate using Dry-Stabilized Rhodopseudomonas palustris

“…2A). By controlling the pressing and drying conditions the authors were able to transfer their expertise on the preservation of cellular viability in latex coatings (Gosse et al 2012;Bernal et al 2014;Estrada et al 2015) to the fabrication of this paper-based cellular biocomposite. It was also evident from the H2 production data that the manufacturing conditions played a critical role on the final reactivity of the microbial paper sheet.…”

“…These characteristics also make them convenient model organisms for studies on cellular immobilization (Gosse et al 2007(Gosse et al , 2010(Gosse et al , 2012, photobioreactor design and illumination optimization (Adessi and De Philippis 2014), and pigment content manipulation at the molecular level (Ma et al 2012) to improve H2 production yields under anoxic conditions. Immobilized systems including PNSBs are an integral component of the current efforts to bring microbial hydrogen production to the marketplace (Show et al 2012).…”

Hydrogen Photoproduction by Immobilized N 2 -Fixing Cyanobacteria: Understanding the Role of the Uptake Hydrogenase in the Long-Term Process

“…There are several different techniques that can be considered for further improvements, including natural biofilm formation on translucent matrices and latex coatings (29). Latex coatings (28,30), including the wet coalescence approach (31), are promising methods for the entrapment of phototrophic organisms, but these methods are not usually as efficient as hydrogels for the immobilization of H 2 -producing microalgae and cyanobacteria. Recently, a technique for entrapment of eukaryotic microalgae within thin-layer alginate matrices has been developed, which has demonstrated 1.5% conversion efficiency of light energy to H 2 (32).…”