Carbon Dioxide Utilisation -The Formate Route

UIDB/50006/2020 CEEC-Individual 2017 Program Contract.The relentless rise of atmospheric CO2 is causing large and unpredictable impacts on the Earth climate, due to the CO2 significant greenhouse effect, besides being responsible for the ocean acidification, with consequent huge impacts in our daily lives and in all forms of life. To stop spiral of destruction, we must actively reduce the CO2 emissions and develop new and more efficient “CO2 sinks”. We should be focused on the opportunities provided by exploiting this novel and huge carbon feedstock to produce de novo fuels and added-value compounds. The conversion of CO2 into formate offers key advantages for carbon recycling, and formate dehydrogenase (FDH) enzymes are at the centre of intense research, due to the “green” advantages the bioconversion can offer, namely substrate and product selectivity and specificity, in reactions run at ambient temperature and pressure and neutral pH. In this chapter, we describe the remarkable recent progress towards efficient and selective FDH-catalysed CO2 reduction to formate. We focus on the enzymes, discussing their structure and mechanism of action. Selected promising studies and successful proof of concepts of FDH-dependent CO2 reduction to formate and beyond are discussed, to highlight the power of FDHs and the challenges this CO2 bioconversion still faces.publishersversionpublishe

American Journal of Veterinary Research 49 7 1134 1142 UNITED STATES

Pituitary function and short-term clinical effects after transsphenoidal hypophysectomy were investigated in clinically normal dogs. In study I, 8 dogs were given polyionic fluids IV during the first 12 hours after surgery. In study II, 4 dogs were given polyionic fluids IV and glucocorticoid supplementation for 7 days. Pituitary function was assessed by evaluating basal ACTH concentrations and results of a growth hormone stimulation test before and 1 and 12 weeks after hypophysectomy, an ACTH stimulation test, a thyrotropin-releasing hormone-stimulation test, and a modified water deprivation/vasopressin response test before and 1, 4, 8, and 12 weeks after hypophysectomy. Gross and histologic evaluations of the surgery site, thyroid and adrenal glands, and skin were done at 12 weeks after surgery. Four dogs from study I died within 27 hours after hypophysectomy. Postmortem examinations of these dogs revealed liver and lung congestion compatible with circulatory collapse. None of the dogs in study II died. For the surviving dogs in both studies, diabetes insipidus developed immediately after hypophysectomy and resolved within 2 weeks. Hypernatremia also developed immediately after hypophysectomy and resolved by 1 week. Production of ACTH was evident at 1 and 12 weeks after hypophysectomy in all dogs, and results of ACTH stimulation tests after surgery were not notably different from results obtained before surgery. Results of thyrotropin-releasing hormone stimulation and growth hormone-stimulation tests supported the diagnosis of hypothyroidism and hyposomatotropism attributable to hypophysectomy. Histologic examination revealed thyroid atrophy, epidermal and dermal atrophy, and normal adrenal glands in all dogs and remnants of the hypophysis in 2 dogs from study I.(ABSTRACT TRUNCATED AT 250 WORDS