Complete factorial design to adjust pH and sugar concentrations in the inoculum phase of Ralstonia solanacearum to optimize P(3HB) production.

Poly(3-hydroxybutyrate) (P(3HB)) is a biodegradable plastic biopolymer that accumulates as lipophilic inclusions in the cytoplasm of some microorganisms. The biotechnological process by which P(3HB) is synthesized occurs in two phases. The first phase involves cell growth in a complex culture medium, while the second phase involves polymer accumulation in the presence of excess carbon sources. As such, the efficiency of the second phase depends on the first phase. The aim of this study was to evaluate culture media with different concentrations of sucrose and glucose and different pH values in the inoculum phase of Ralstonia solanacearum RS with the intention of identifying methods by which the biomass yield could be increased, subsequently enhancing the yield of P(3HB). The culture medium was formulated according to the experimental planning type of central composite rotational design 22. The independent variables were pH and sugar concentration (sucrose and glucose), and the dependent variables were OD600nm, dry cell weight (DCW), and P(3HB) yield. The highest cell growth, estimated by the OD600nm (20.6) and DCW (5.35) values, was obtained when sucrose was used in the culture medium at a concentration above 35 g.L-1 in combination with an acidic pH. High polymer (45%) accumulation was also achieved under these conditions. Using glucose, the best results for OD600nm (12.5) and DCW (2.74) were also obtained at acidic pH but with a sugar concentration at the minimum values evaluated. Due to the significant accumulation of polymer in the cells that were still in the growth phase, the accumulating microorganism P(3HB) Ralstonia solanacearum RS can be classified as having type II metabolism in relation to the polymer accumulation phase, which is different from other Ralstonia spp. studied until this time.

Açúcar mascavo em geleiadas de maçã

The work had the objective to elaborate apple jellies by using brown sugar. The jellies were elaborated with apple pulp, water, lemon juice, pectin and 20, 35, 50 and 65% of brown sugar. It was verified the yield, cost and the consumer's preference of the jelly formulations. The most favorite jellies, were reprocessed, and it was determined the physical, chemical and microbiological characteristics, soon after the processing, after 30, 60 and 90 days of storage. It was observed that the jellies elaborated with 35, 50 and 65% of brown sugar were equally acceptable by the consumers, overcoming that ones with 20%; the jelly with 65% of brown sugar presented advantages over the others, when considering the cost and yield; the products stability was superior to three months and there were a physical and chemical significative difference among the formulations.

O trabalho objetivou elaborar geleiadas de maçã utilizando açúcar mascavo. As geleiadas foram elaboradas com polpa de maçã, água, suco de limão, pectina e 20, 35, 50 e 65% de açúcar mascavo em relação à quantidade de polpa. Verificou-se o rendimento, custo, e a preferência do consumidor pelas diferentes formulações. As geleiadas mais preferidas foram reelaboradas e determinaram-se as características físicas, químicas e microbiológicas, logo após o processamento, aos 30, 60 e 90 dias de estocagem. Os resultados permitiram concluir que as geleiadas elaboradas com 35, 50 e 65% de açúcar mascavo foram igualmente preferidas pelos consumidores, superando aquela com 20%; considerando o custo e o rendimento, verificou-se que a geleiada com 65% de açúcar mascavo apresentou vantagem sobre as demais; a estabilidade desses produtos foi superior a três meses; e existiram diferenças físicas e químicas significativas entre as formulações.

Açúcar mascavo em geleiadas de maçã

The work had the objective to elaborate apple jellies by using brown sugar. The jellies were elaborated with apple pulp, water, lemon juice, pectin and 20, 35, 50 and 65% of brown sugar. It was verified the yield, cost and the consumer's preference of the jelly formulations. The most favorite jellies, were reprocessed, and it was determined the physical, chemical and microbiological characteristics, soon after the processing, after 30, 60 and 90 days of storage. It was observed that the jellies elaborated with 35, 50 and 65% of brown sugar were equally acceptable by the consumers, overcoming that ones with 20%; the jelly with 65% of brown sugar presented advantages over the others, when considering the cost and yield; the products stability was superior to three months and there were a physical and chemical significative difference among the formulations.

O trabalho objetivou elaborar geleiadas de maçã utilizando açúcar mascavo. As geleiadas foram elaboradas com polpa de maçã, água, suco de limão, pectina e 20, 35, 50 e 65% de açúcar mascavo em relação à quantidade de polpa. Verificou-se o rendimento, custo, e a preferência do consumidor pelas diferentes formulações. As geleiadas mais preferidas foram reelaboradas e determinaram-se as características físicas, químicas e microbiológicas, logo após o processamento, aos 30, 60 e 90 dias de estocagem. Os resultados permitiram concluir que as geleiadas elaboradas com 35, 50 e 65% de açúcar mascavo foram igualmente preferidas pelos consumidores, superando aquela com 20%; considerando o custo e o rendimento, verificou-se que a geleiada com 65% de açúcar mascavo apresentou vantagem sobre as demais; a estabilidade desses produtos foi superior a três meses; e existiram diferenças físicas e químicas significativas entre as formulações.