Biology subjects

Alonso, J. C.

Publications and source records attributed to Alonso, J. C..

4 recordsLinked to original sources

bioRxiv2021

What do we know about survival of Common cranes? An elementary introduction with Euring databank

The increase of the western populations of Common cranes (Grus grus) in the last five decades highlights the need to estimate survival rates. According to Euring databank (EDB), the oldest Common crane ever known was 27 years old in year 2017. This lifespan was obtained by means of 24,900 recoveries of 2,124 ringed cranes collected between years 1936 and 2017. Nearly all cranes were ringed and observed in the last 30 years, and therefore the elapsed time was not enough to reach the maximum longevity reported for the species in captivity (43 years, Mitchell 1911). Life expectancy was five years on average after the ring was attached. Here we provide some elementary analyses to calculate the annual apparent survival rate ({phi} = 0.85) and the annual encounter probability (p = 0.45) of Common cranes, as a first step to advance in the knowledge of the species population dynamics. The great increase of breeding and wintering crane populations in western Europe in the last decades remains largely unexplained.

zoology↗

bioRxiv2021

Low cost and sustainable hyaluronic acid production in a manufacturing platform based on Bacillus subtilis 3NA strain

Hyaluronic acid (HA) is a high value glycosaminoglycan mostly used in health and cosmetic applications. Commercial HA is produced from animal tissues or in toxigenic bacteria of the genus Streptococcus grown in complex media, which are expensive and raise environmental concerns due to the disposal of large amounts of broth with high organic loads. Other microorganisms were proposed as hosts for the heterologous production of HA, but the methods are still costly. The extraordinary capacity of this biopolymer to bind and retain water attracts interest for large scale applications where biodegradable materials are needed, but its high cost and safety concerns are barriers for its adoption. Bacillus subtilis 3NA strain is prototrophic, amenable for genetic manipulation, GRAS, and can rapidly reach high cell densities in salt-based media. These phenotypic traits were exploited to create a platform for biomolecule production using HA as a proof of concept. First, the 3NA strain was engineered to produce HA; second, a chemically defined medium was formulated using commodity-priced inorganic salts combined at the stoichiometric ratios needed to build the necessary quantities of biomass and HA; and third, a scalable fermentation process, where HA can be produced at the maximum volumetric productivity (VP), was designed. A comparative economic analysis against other methods indicates that the new process may increase the operating profit of a manufacturing plant by more than 100 %. The host, the culture medium, and the rationale employed to develop the fermentation process described here, introduce an IP free platform that could be adaptable for production of other biomolecules. Key PointsO_LIA platform for the production of biomolecules was designed based on B. subtilis 3NA, a chemically defined medium and a fermentation process. C_LIO_LIAs proof of concept, high quality hyaluronic acid was produced with an environmentally friendly process. C_LIO_LIA techno-economic analysis indicates that the process is more that 100% profitable than current methods. C_LI

bioengineering↗

bioRxiv2020

DisA limits RecA- and RadA/Sms-mediated replication fork remodelling to prevent genome instability

The DisA diadenylate cyclase (DAC), the DNA helicase RadA/Sms and the RecA recombinase are required to prevent a DNA replication stress during the revival of haploid Bacillus subtilis spores. Moreover, disA, radA and recA are epistatic among them in response to DNA damage. We show that DisA inhibits the ATPase activity of RadA/Sms C13A by competing for single-stranded (ss) DNA. In addition, DisA inhibits the helicase activity of RadA/Sms. RecA filamented onto ssDNA interacts with and recruits DisA and RadA/Sms onto branched DNA intermediates. In fact, RecA binds a reversed fork and facilitates RadA/Sms-mediated unwinding to restore a 3'-fork intermediate, but DisA inhibits it. Finally, RadA/Sms inhibits DisA DAC activity, but RecA counters this negative effect. We propose that RecA, DisA and RadA/Sms interactions, which are mutually exclusive, limit remodelling of stalled replication forks. DisA, in concert with RecA and/or RadA/Sms, indirectly contributes to template switching or lesion bypass, prevents fork breakage and facilitates the recovery of c-di-AMP levels to re-initiate cell proliferation. Subject CategoriesGenomic stability & Dynamics

microbiology↗

bioRxiv2020

Recombination proteins differently control the acquisition of homeologous DNA during Bacillus subtilis natural chromosomal transformation

In naturally competent Bacillus subtilis cells the acquisition of closely related genes occurs via homology-directed chromosomal transformation (CT), and its frequency decreases log-linearly with increased sequence divergence (SD) up to 15%. Beyond this and up to 23% SD the interspecies boundary prevails, the CT frequency marginally decreases, and short (<10-nucleotides) segments are integrated via homology-facilitated micro-homologous integration. Both poorly known CT mechanisms are RecA-dependent. Here we identify the recombination proteins required for the acquisition of interspecies DNA. The absence of AddAB, RecF, RecO, RuvAB or RecU, crucial for repair-by-recombination, does not affect CT. However, inactivation of dprA, radA, recJ, recX or recD2 strongly interfered with CT. Interspecies CT was abolished beyond ~8% SD in {Delta}dprA, ~10% in {Delta}recJ, {Delta}radA, {Delta}recX and 14% in {Delta}recD2 cells. We propose that DprA, RecX, RadA/Sms, RecJ and RecD2 help RecA to unconstrain speciation and gene flow. These functions are ultimately responsible for generating genetic diversity and facilitate CT and gene acquisition from bacteria of the same genus.

microbiology↗