*Correspondence: Liz M. Díaz-Vázquez, Lab CN 202A, Department of Chemistry, University of Puerto Rico Rio Piedras Campus, Barbosa Ave-Ponce de León Avenue, San Juan, PR 00931, USA e-mail: [email protected]; [email protected] Algae biomasses are considered a viable option for the production of biofuel because of their high yields of oil produced per dry weight. Brown macroalgae Sargassum spp...

A sequential optimization based on statistical design and one-factor-at-a-time (OFAT) method was employed to optimize the media constituents for the improvement of citric acid production from oil palm empty fruit bunches (EFB) through solid state bioconversion using Aspergillus niger IBO-103MNB. The results obtained from the Plackett-Burman design indicated that the co-substrate (sucrose), stim...

Hypoxia triggers several mechanisms to adapt cells to a low oxygen environment. Mitochondria are major consumers of oxygen and a potential source of reactive oxygen species (ROS). In response to hypoxia they exchange or modify distinct subunits of the respiratory chain and adjust their metabolism, especially lowering the citric acid cycle. Intermediates of the citric acid cycle participate in r...

There has been a steady increase in the consumption of citric acid during the past 25 years. An estimate by Cochrane (1948) places annual manufacture at approximately 35 million pounds. Commercial production of citric acid is reputedly based on fermentation by Aspergillus niger of a suitable grade of beet syrup in shallow pans. A submerged process appears to be highly desirable, and many articl...

the postharvest life of cut eustoma grandiflorum flowers is limited in open flowers. therefore a factorial experiment based on a completely randomized design with ascorbic acid (asa) at 4 levels (0, 100, 200, 300mg l-1) and citric acid (ca) at 3 levels (0, 100, 200 mg l-1) with 3 replications and 3 samples for each replications, was conducted for this purpose. results indicated that a significa...

Citric acid may be involved in plant response to high temperature. The objective of this study was to investigate whether exogenous citric acid could improve heat tolerance in a cool-season turfgrass species, tall fescue (Lolium arundinaceum), and to determine the physiological mechanisms of citric acid effects on heat stress tolerance. The grasses were subjected to four citric acid levels (0, ...

introduction: the production of smear layer during canal instrumentation is thought to increase coronal microleakage even after canal obturation. previous studies have shown that the type of irrigant does not necessarily affect the seal of the obturation. our study aimed to evaluate the effect of three irrigation solutions (mtad, citric acid and edta/naocl) on the coronal microleakage of root c...

The aim of this study was to determine the effect of the supplementation of an organic acid (citric acid), antibiotic growth promoter (avilamycin), and their combination for a period of 35 d on the growth, feed efficiency, carcass yield, tibia ash, and immune status of broilers. One hundred sixty 1-d-old broiler chicks (Hubbard Classic) were randomly distributed into 4 groups with 4 replicate c...

The external pH appeared to be the main factor governing oxalic acid production by Aspergillus niger. A glucose-oxidase-negative mutant produced substantial amounts of oxalic acid as long as the pH of the culture was 3 or higher. When pH was decreased below 2, no oxalic acid was formed. The activity of oxaloacetate acetylhydrolase (OAH), the enzyme believed to be responsible for oxalate formati...