Latest Articles

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  Section: Microbiology ; Topics: Microbiology, Sustainability science

  A newly identified Comamonas serinivorans strain for PHA production from sterile-filtered dark-fermentation-derived volatile fatty acids: isolation, metabolic profiling and industrial prospects.

  Gautier, Kelvin; Pattyn, Pauline; Briki, Amani;   Soric, Audrey;   Irague, Romain  

  10.24072/pcjournal.785 - Peer Community Journal, Volume 6 (2026), article no. e90

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  Dark-fermentation for hydrogen production leaves a substantial fraction of substrate carbon unexploited, with a large fraction remaining as volatile fatty acids (VFAs), mainly acetate and butyrate. To improve process valorisation, this study investigates the microbial conversion of fermentation-derived VFAs into polyhydroxyalkanoates (PHAs). A PHA-producing strain was isolated from dairy wastewater sludge using a feast-famine enrichment strategy and identified as Comamonas serinivorans ATH based on 16S rRNA gene sequencing. The strain exhibited strict specialisation towards organic acids, efficiently assimilating VFAs but not carbohydrates. Under nutrient limitation, intracellular PHA accumulation reached up to 93% of cell dry weight. When cultivated in a sterile-filtered dark-fermentation stream, the strain consumed both acetate and butyrate and produced PHA with a yield of 0.54 g/g of consumed VFAs under non-optimised conditions. GC-MS analysis confirmed that Comamonas serinivorans ATH produces a polymer mainly composed of 3-hydroxybutyrate monomers. These findings demonstrate the feasibility of coupling hydrogen-producing dark-fermentation with PHA synthesis, supporting an integrated biorefinery approach for sustainable bioplastic production from waste-derived carbon streams.

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  Section: Forest & Wood Sciences ; Topics: Ecology, Population biology, Genetics/genomics

  Impact of selective logging on the population dynamics and genetic diversity in the neotropical timber tree Dicorynia guianensis

  Bonnier, Julien;   Traissac, Stephane;   Brunaux, Olivier;   Troispoux, Valerie;   Tysklind, Niklas;   Heuertz, Myriam  

  10.24072/pcjournal.779 - Peer Community Journal, Volume 6 (2026), article no. e89

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  Selective logging is a widely applied forest management strategy in the tropics, yet it is insufficiently documented how it affects the genetic and demographic processes of seedling recruitment in timber species in the Guiana Shield. Our study investigates how selective logging influences genetic diversity, gene dispersal, and seedling establishment in Dicorynia guianensis by comparing a logged and an unlogged forest plot in French Guiana. We genotyped 703 individuals using 66 nuclear SSR markers and applied parentage analyses to infer dispersal patterns and reproductive success. We analysed genetic diversity and spatial genetic structure across life stages, and tested whether seedling recruitment was associated with logging-related canopy openings. Genetic diversity indices were broadly similar between logged and unlogged plots, with no evidence of genetic erosion in adults or seedlings. Seedling establishment was associated with logging-induced canopy openings. Parentage analyses revealed shorter mean dispersal distances in the logged plot but substantial long-distance pollen flow, ensuring admixture and inter-plot connectivity. Reproductive success was more evenly distributed among mothers, whereas male contributions were skewed in the logged plot. Selective logging did not cause immediate genetic erosion but altered dispersal dynamics and reproductive patterns. These findings underline the resilience of D. guianensis under current management practices, while emphasizing the need for long-term monitoring of regeneration to ensure sustainable recruitment and evolutionary resilience across logging cycles.

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  Section: Ecology ; Topics: Ecology, Applied mathematics

  SIESTR: a novel method to analyze Species’ Introductions Effects in Space and Time on Range dynamics

  Callebaut, Arnaud;   Gégout, Jean-Claude;   Serra-Diaz, Josep M.  

  10.24072/pcjournal.763 - Peer Community Journal, Volume 6 (2026), article no. e88

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  Rapidly shifting climates will lead to species range shifts over the next century. Artificially introducing species in new locations to enhance species migration, termed assisted migration (AM), has been suggested as one possible strategy to avoid species extinction. While current models of range shift are used to explore potential future areas of introduction, we lack a method able to identify the best sets of locations and timing for species introductions that maximize AM outcomes. We developed a novel method to explore the effects of Species’ Introduction Effects in Space and Time on Range dynamics (SIESTR). The method uses transition matrices that combine spatial and temporal species’ environmental suitability changes and dispersal information. A metaheuristic algorithm is run to achieve an objective target of range area optimizing locations and times of species introductions, while minimizing spatially explicit cost surfaces. We apply the method to a virtual species to showcase the potential of SIESTR to explore the maintenance of range size under climate change via artificial introductions. We assess optimal AM strategies under climate change and with different land use cost scenarios. We found a strong effect of early introductions enhancing species range shifts, as well as differences in introduction sites and timing under different cost scenarios. SIESTR is a fast and efficient technique for exploration of range shifts under artificial introductions, tackling both the spatial and temporal dimensions. The method has been developed in Cpp, available as an R package. Given the heated debate around AM and introductions, our method provides a new tool to explore strategies in spatial conservation planning in the Anthropocene.

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  Section: Ecology ; Topics: Ecology, Agricultural sciences, Sustainability science

  Ground beetles in agroforestry system show functional traits and activity-density differences according to distance to trees

  Kletty, Florian;   Deville, Pascal; Devigne, Cédric; Machelart, Sophie; Benamrouz-Vanneste, Sadia;   Vanhée, Benoît

  10.24072/pcjournal.780 - Peer Community Journal, Volume 6 (2026), article no. e87

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  Alley-cropping systems are arable agroforestry systems in which tree rows and associated grassy strips are established within cropped fields. This constitutes a promising approach to promote biodiversity and associated services in the vicinity of crops. However, there is still little knowledge on the functioning of these systems, especially when they are developed in combination with other agroecological practices or models. We studied ground beetle (Carabidae) communities in such silvoarable systems (SAS), with a particular focus on the effect of distance to tree rows. The studied fields were managed using conservation agriculture practices, namely no-tillage, cover crop maximisation, and crop diversification, carried out over the long term. This study aimed to assess the response of carabid beetle communities to these specific but promising agroecological systems. Ground beetle activity-density, which reflects both abundance and activity, was higher in crop alleys than in tree rows. We did not detect clear differences in species richness or overall community composition along the distance gradient from tree rows. However, diversity patterns based on effective diversity revealed marked structural differences, with communities near tree rows being more diverse, whereas carabid assemblages within crop alleys, especially at 20m from tree rows, were increasingly dominated by a limited number of abundant species. Consistent with these structural patterns, functional trait composition varied with distance to trees, with crop alleys harbouring less winged, less zoophagous communities and a higher proportion of adult-overwintering species, while larger species were more frequent in the middle of crop alleys. SAS associated with conservation agriculture therefore exhibit strong potential to support biocontrol services and promote carabid communities that are resilient to climatic or agronomic perturbations. Further studies are needed to understand the functioning of ecosystems by integrating other taxonomic groups and abiotic factors.