RESUMEN
Two recombinants of alkaliphilic Bacillus subtilis LOCK 1086, constructed via different strategies such as cloning the gene encoding bacterial hemoglobin from Vitreoscilla stercoraria (vhb) and overexpression of the gene encoding acetoin reductase/2,3-butanediol dehydrogenase (bdhA) from B. subtilis LOCK 1086, did not produce more 2,3-butanediol (2,3-BD) than the parental strain. In batch fermentations, this strain synthesized 9.46 g/L in 24 h and 12.80 g/L 2,3-BD in 46 h from sugar beet molasses and an apple pomace hydrolysate, respectively. 2,3-BD production by B. subtilis LOCK 1086 was significantly enhanced in fed-batch fermentations. The highest 2,3-BD concentration (75.73 g/L in 114 h, productivity of 0.66 g/L × h) was obtained in the sugar beet molasses-based medium with four feedings with glucose. In a medium based on the apple pomace hydrolysate with three feedings with sucrose, B. subtilis LOCK 1086 produced up to 51.53 g/L 2,3-BD (in 120 h, productivity of 0.43 g/L × h).
Asunto(s)
Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Butileno Glicoles/metabolismo , Ingeniería Metabólica/métodos , Redes y Vías Metabólicas/genética , Beta vulgaris/metabolismo , Fermentación , Expresión Génica , Residuos Industriales , Malus/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Recombinación Genética , Vitreoscilla/enzimología , Vitreoscilla/genéticaRESUMEN
A nonpathogenic bacterial strain Bacillus amyloliquefaciens TUL 308 synthesized minor 2,3-butanediol (2,3-BD) amounts from glucose, fructose, sucrose, and glycerol, and efficiently produced the diol from molasses and hydrolysates of food processing residues. Batch fermentations yielded 16.53, 10.72, and 5 g/L 2,3-BD from enzymatic hydrolysates of apple pomace, dried sugar beet pulp, and potato pulp (at initial concentrations equivalent to 45, 20, and 30 g/L glucose, respectively), and 25.3 g/L 2,3-BD from molasses (at its initial concentration equivalent to 60 g/L saccharose). Fed-batch fermentations in the molasses-based medium with four feedings with either glucose or sucrose (in doses increasing their concentration by 25 g/L) resulted in around twice higher maximum 2,3-BD concentration (of about 60 and 50 g/L, respectively). The GRAS Bacillus strain is an efficient 2,3-BD producer from food industry byproducts.
Asunto(s)
Bacillus amyloliquefaciens/metabolismo , Butileno Glicoles/metabolismo , Manipulación de Alimentos , Beta vulgaris/metabolismo , Biomasa , Reactores Biológicos , Cromatografía Líquida de Alta Presión , Medios de Cultivo , Fermentación , MelazaRESUMEN
2,3-Butanediol (2,3-BD) synthesis by a nonpathogenic bacterium Bacillus licheniformis NCIMB 8059 from enzymatic hydrolysate of depectinized apple pomace and its blend with glucose was studied. In shake flasks, the maximum diol concentration in fed-batch fermentations was 113 g/L (in 163 h, from the hydrolysate, feedings with glucose) while in batch processes it was around 27 g/L (in 32 h, from the hydrolysate and glucose blend). Fed-batch fermentations in the 0.75 and 30 L fermenters yielded 87.71 g/L 2,3-BD in 160 h, and 72.39 g/L 2,3-BD in 94 h, respectively (from the hydrolysate and glucose blend, feedings with glucose). The hydrolysate of apple pomace, which was for the first time used for microbial 2,3-BD production is not only a source of sugars but also essential minerals.
Asunto(s)
Aspergillus niger/enzimología , Bacillus/metabolismo , Butileno Glicoles/metabolismo , Malus/química , Malus/metabolismo , Técnicas de Cultivo Celular por Lotes , Reactores Biológicos/microbiología , Fermentación , Glucosa/metabolismo , HidrólisisRESUMEN
The rising population of older Americans with advanced illness challenges current care delivery models. We use the metaphor of advanced illness as a difficult journey and propose a specific role, that of the "OACIS NP [nurse practitioner]," who helps provide a place of refuge during this journey. "OACIS" is an acronym for Optimizing Advanced Complex Illness Support, a program to provide home-based palliative medical care. The 4 pillars of this collaborative model for advanced nursing care include care coordination, medical management, psychosocial support, and education. We make the case for this expanded role for nurse practitioners who specialize in palliative care.