Biology subjects

Salmela, M.

Publications and source records attributed to Salmela, M..

3 recordsLinked to original sources

bioRxiv2024

Natural variation in circadian period correlates with diverse phenological measures in Boechera stricta

The circadian clock is a time-keeping mechanism that enables adaptive responses to temporal environmental changes. Circadian period exhibits significant segregating genetic variation within and among populations along an elevational cline, potentially resulting from variable selection across microsites on outputs of the circadian clock. Reproductive timing is an important clock output and selection may favor delayed phenology. We performed a three-year common garden field study with the short-lived perennial Boechera stricta to quantify life history differences among 20 populations from an elevational gradient and among 20 maternal families within one population. We measured days to bolting and later life history transitions such as days to flowering; in the same genotypes, we measured circadian period. The timing of all life history transitions varied among growing seasons, suggesting adaptive life history evolution to local climate conditions. Life history transitions after bolting were also associated with circadian period, such that lengthened period was associated with delayed life history transitions. Structural equation modeling indicated that indirect selection via days to flowering and fruit production favored lengthened clock period in the low elevation common garden site, suggesting that selection on phenology could explain the evolution of variable circadian periods observed among populations from differing environments.

plant biology↗

bioRxiv2018

Alkane and wax ester production from lignin derived molecules

Lignin has potential as a sustainable feedstock for microbial production of industrially relevant molecules. However, the required lignin depolymerization yields a heterogenic mixture of aromatic monomers that are challenging substrates for the microorganisms commonly used in industry. Here, we investigated the properties of lignin-derived molecules (LDMs), namely coumarate, ferulate, and caffeate, in the synthesis of biomass and products in a LDM-utilizing bacterial host Acinetobacter baylyi ADP1. The biosynthesis products, wax esters and alkanes, are relevant compounds for the chemical and fuel industries. In A. baylyi ADP1, wax esters are produced by a native pathway, whereas alkanes are produced by a synthetic pathway introduced to the host. Using individual LDMs as substrates, the growth, product formation, and toxicity to cells were monitored with internal biosensors. Of the tested LDMs, coumarate was the most propitious in terms of product synthesis. Wax esters were produced from coumarate with a yield and titer of 40 mg /gcoumarate and 221 mg/L, whereas alkanes were produced with a yield of 62.3 g /gcoumarate and titer of 152 g/L. This study demonstrates the microbial preference for certain LDMs, and highlights the potential of A. baylyi ADP1 as a convenient host for LDM upgrading to value-added products.

bioengineering↗

bioRxiv2018

Metabolic pairing of aerobic and anaerobic production in a one-pot batch cultivation

BackgroundThe versatility of microbial metabolic pathways enables their utilization in vast number of applications. However, the electron and carbon recovery rates, essentially constrained by limitations of cell energetics, are often too low in terms of process feasibility. Cocultivation of divergent microbial species in a single process broadens the metabolic landscape and thus, the possibilities for more complete carbon and energy utilization.\n\nResultsIn this study, we integrated the metabolisms of two bacteria, an obligate anaerobe Clostridium butyricum and an obligate aerobe Acinetobacter baylyi ADP1. In the process, a glucose-negative mutant of A. baylyi ADP1 first deoxidized the culture allowing C. butyricum to grow and produce hydrogen from glucose. In the next phase, ADP1 produced long chain alkyl esters utilizing the by-products of C. butyricum, namely acetate and butyrate.\n\nConclusionsThe cocultivation of strictly anaerobic and aerobic bacteria allowed the production of both hydrogen gas and long-chain alkyl esters in a simple one-pot batch process. The study demonstrates the potential of metabolic pairing using designed microbial consortia for optimal electron and carbon recovery.

bioengineering↗