No abstract

The effect of liquid (LSF) and solid state fermentation (SSF) of lentils for production of water-soluble fractions with antioxidant and antihypertensive properties was studied. LSF was performed either spontaneously (NF) or by Lactobacillus plantarum (LP) while SSF was performed by Bacillus subtilis (BS). Native lactic flora in NF adapted better than L. plantarum to fermentative broth and BS counts increased 4.0 logCFU/g up to 48 h of SSF. LSF water-soluble fractions had higher (P ≤ 0.05) free amino groups, GABA content, antioxidant and angiotensin I-converting enzyme inhibitory (ACEI) activities than SSF. In addition, GABA and ACEI activity of LSF increased in a time-dependent manner. Proteolysis by BS was limited, with slight changes in free amino groups, while GABA, total phenolic compounds and antioxidant capacity increased throughout fermentation. Higher antihypertensive potential was observed in NF (96 h) characterised by the highest GABA content (10.42 mg/g extract), ACE-inhibitory potency (expressed as IC(50)) of 0.18 mg protein/ml and antioxidant capacity of 0.26 mmol Trolox equivalents/g extract. Therefore, water-soluble fermented lentil extracts obtained by LSF are particularly promising as functional ingredients in preventing hypertension.

Lactic acid bacteria (LAB) are microorganisms widely used in the fermented food industry worldwide. Certain LAB are able to produce exopolysaccharides (EPS) either attached to the cell wall (capsular EPS) or released to the extracellular environment (EPS). According to their composition, LAB may synthesize heteropolysaccharides or homopolysaccharides. A wide diversity of EPS are produced by LAB concerning their monomer composition, molecular mass, and structure. Although EPS-producing LAB strains have been traditionally applied in the manufacture of dairy products such as fermented milks and yogurts, their use in the elaboration of low-fat cheeses, diverse type of sourdough breads, and certain beverages are some of the novel applications of these polymers. This work aims to collect the most relevant issues of the former reviews concerning the monomer composition, structure, and yields and biosynthetic enzymes of EPS from LAB; to describe the recently characterized EPS and to present the application of both EPS-producing strains and their polymers in the fermented (specifically beverages and cereal-based) food industry.

The influence of solid (SSF) or liquid state fermentation (LSF) for 48 and 96 h on the production of water soluble extracts from kidney beans was investigated. SSF was carried out by Bacillus subtilis, whilst LSF was performed either by natural fermentation (NF) or by Lactobacillus plantarum strain (LPF). SSF extracts showed high soluble phenolic compound content (31-36 mg/g) and antioxidant activity (508-541 μg trolox equivalents/g), whilst LSF extracts exhibited potential antihypertensive activity due to their large γ-aminobutyric acid (GABA) content (6.8-10.6 mg/g) and angiotensin converting enzyme inhibitory (ACEI) activity (>90%). Therefore, fermentation can be considered as a valuable process to obtain bioactive ingredients from kidney beans, which could encourage their utilisation in the formulation of added-value functional foods.

CLIBASIA_01510, PrbP, is a predicted RNA polymerase binding protein in Liberibacter asiaticus. PrbP was found to regulate expression of a small subset of ribosomal genes through interactions with the β-subunit of the RNA polymerase and a short, specific sequence on the promoter region. Molecular screening assays were performed to identify small molecules that interact with PrbP in vitro. Chemical hits were analyzed for therapeutic efficacy against L. asiaticus via an infected leaf assay, where the transcriptional activity of L. asiaticus was found to decrease significantly after exposure to tolfenamic acid. Similarly, tolfenamic acid was found to inhibit L. asiaticus infection in highly symptomatic citrus seedlings. Our results indicate that PrbP is an important transcriptional regulator for survival of L. asiaticus in planta, and the chemicals identified by molecular screening assays could be used as a therapeutic treatment for huanglongbing disease.