Biology subjects

Lens, P. N. L.

Publications and source records attributed to Lens, P. N. L..

4 recordsLinked to original sources

bioRxiv2026

LANTHANUM (LaCl3) ADDITION DIVERSIFIES ORGANIC ACID PRODUCTION AND SIGNIFICANTLY ENHANCES METHANE PRODUCTION IN A METHANOGENIC CONSORTIUM

Trace elements, such as iron, nickel, and cobalt are known to regulate methanogenic activity in anaerobic digestors used for waste valorisation, but the potential role of rare earth elements remains poorly understood. This study investigated the effects of lanthanum (La) supplementation on biogas production, methane generation, volatile fatty acid (VFA) formation, and carbohydrate utilisation in anaerobic digestion (AD). Biomethane potential (BMP) assays conducted under mesophilic conditions (37C) using methanogenic sludge granules, and glucose as substrate, were supplemented with 0.1, 1, 10, and 100 mg/L lanthanum chloride (LaCl3). Biogas production and composition was monitored over a 96-h incubation, while sacrificial, batch bioreactors were used to evaluate temporal VFA and carbohydrate profiles. La supplementation significantly enhanced biogas and methane production in a concentration-dependent manner. The highest cumulative biogas yield (478.9 mL, corresponding to 179.5 mL biogas/g COD) and methane production (285.7 mL, corresponding to 107.1 mL CH4/g COD) were observed with 100 mg/L LaCl3, corresponding to increases of 88.7% and 186%, respectively, compared with La-free controls. CO2 production also increased with La concentration, whereas hydrogen production remained comparatively low. Acetic and butyric acids represented the dominant fermentation products (80-88% of total VFAs), but profiles of accumulated VFA in the bioreactors diversified with La addition, including showing caproate production, indicating changed biodegradation dynamics in the methanogenic microbiome. These findings demonstrate that lanthanum can stimulate anaerobic digestion performance and methane generation, highlighting the potential as a novel trace element additive to enhance biogas production. Research is now required to elucidate the underlying microbial and biochemical mechanisms, and establish optimal dosing strategies for large-scale applications.

microbiology↗

bioRxiv2021

ASSEMBLY AND DYNAMICS OF MICROBIAL COMMUNITIES IN GRANULAR, FIXED-BIOFILM AND PLANKTONIC METHANOGENIC MICROBIOMES VALORIZING LONG CHAIN FATTY ACID (LCFA)-RICH WASTEWATER

Distinct microbial assemblages are engineered in anaerobic digestion (AD) reactors to drive sequential conversions of organics to methane. The spatio-temporal development of three such assemblages (granules, biofilms, planktonic) derived from the same inoculum was studied in replicated bioreactors treating long-chain fatty acids (LCFA)-rich wastewater at 20{degrees}C at hydraulic retention times (HRTs) of 12-72 h. We found granular, biofilm and planktonic assemblages differentiated by diversity, structure, and assembly mechanisms; demonstrating a spatial compartmentalisation of the microbiomes from the initial community reservoir. Our analysis linked abundant Methanosaeta and Syntrophaceae-affiliated taxa (Syntrophus and uncultured) to their putative, active roles in syntrophic LCFA bioconversion. LCFA loading rates (stearate, palmitate), and HRT, were significant drivers shaping microbial community dynamics and assembly. This study of the archaea and syntrophic bacteria actively valorising LCFAs at short HRTs and 20{degrees}C will help uncover the microbiology underpinning anaerobic bioconversions of fats, oil and grease. HighlightsO_LIGranular, biofilm and planktonic assemblages developed from the same seed reservoir C_LIO_LIThree assemblages forming metacommunity differed in diversity and composition C_LIO_LIMultiple null models applied to quantify deterministic and stochastic mechanisms C_LIO_LIDominant, active role of acetoclastic Methanosaeta confirmed in granules and biofilm C_LIO_LIDynamic, non-core-microbiome taxa correlated with environmental variables C_LI

microbiology↗

bioRxiv2021

PyADM1: a Python implementation of Anaerobic Digestion Model No. 1

Anaerobic Digestion (AD) is a waste treatment technology widely used for wastewater and solid waste treatment, with the advantage of being a source of renewable energy in the form of biogas. Anaerobic digestion model number 1 (ADM1) is the most common mathematical model available for AD modelling. Commercial software implementations of ADM1 are available but have limited flexibility and availability due to the closed sources and licensing fees. Python is the fastest growing programming language and is open source freely available. Python implementation of ADM1 makes this AD model available to the mass user base of the Python ecosystem and its libraries. The open easy to use implementation in PyADM1 makes it more accessible and provides possibilities for flexible direct use of the model linked to other software, e.g. machine learning libraries or Linux operating system on embedded hardware.

systems biology↗

bioRxiv2018

Pressure sensitivity of ANME-3 predominant anaerobic methane oxidizing community from coastal marine Lake Grevelingen sediment

Anaerobic oxidation of methane (AOM) coupled to sulfate reduction is mediated by, respectively, anaerobic methanotrophic archaea (ANME) and sulfate reducing bacteria (SRB). When a microbial community from coastal marine Lake Grevelingen sediment, containing ANME-3 as the most abundant type of ANME, was incubated under a pressure gradient (0.1-40 MPa) for 77 days, ANME-3 was more pressure sensitive than the SRB. ANME-3 activity was higher at lower (0.1, 0.45 MPa) over higher (10, 20 and 40 MPa) CH4 total pressures. Moreover, the sulfur metabolism was shifted upon changing the incubation pressure: only at 0.1 MPa elemental sulfur was detected in a considerable amount and SRB of the Desulfobacterales order were more enriched at elevated pressures than the Desulfubulbaceae. This study provides evidence that ANME-3 can be constrained at shallow environments, despite the scarce bioavailable energy, because of its pressure sensitivity. Besides, the association between ANME-3 and SRB can be steered by changing solely the incubation pressure.\n\nImportanceAnaerobic oxidation of methane (AOM) coupled to sulfate reduction is a biological process largely occurring in marine sediments, which contributes to the removal of almost 90% of sedimentary methane, thereby controlling methane emission to the atmosphere. AOM is mediated by slow growing archaea, anaerobic methanotrophs (ANME) and sulfate reducing bacteria. The enrichment of these microorganisms has been challenging, especially considering the low solubility of methane at ambient temperature and pressure. Previous studies showed strong positive correlations between the growth of ANME and the methane pressure, since the higher the pressure the more methane is dissolved. In this research, a shallow marine sediment was incubated under methane pressure gradients. The investigated effect of pressure on the AOM-SR activity, the formation sulfur intermediates and the microbial community structure is important to understand the pressure influence on the processes and the activity of the microorganisms involved to further understand their metabolism and physiology.

microbiology↗