Microflora were investigated in traditional starter cultures for fermented milk, hurunge, which are used for fermented dairy products by nomadic families in the Inner Mongolia Autonomic Region, China. The acid‐forming bacteria and yeast counts ranged from 1.8 × 105 to 5.3 × 108 c.f.u./g and from 6.1 × 105 to 3.2 × 106 c.f.u./g, respectively. Sixty‐six strains of lactic acid bacteria and 30 strains of yeasts were isolated and identified from three hurunge samples collected from the nomadic families. Lactococcus raffinolactis was the most predominant lactococci isolated from these samples. The other lactococci were Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. cremoris, and Leuconostoc mesenteroides ssp. cremoris. Two major lactobacilli strains, Lactobacillus plantarum and Lactobacillus casei, were identified. In addition, Lactobacillus kefiranofaciens, Lactobacillus acetotolerans, which grew in 11% acetic acid culture medium, and Lactobacillus homohiochii, which grew in the culture medium containing 16% ethanol, were also identified. The isolated yeast strains were identified as Candida kefyr, Saccharomyces cerevisiae, Kluyveromyces marxianus var. lactis, Candida krusei and Candida valida.

The antioxidative effects of methanol extracts of crude drugs were estimated by an electrochemical method because there are many electrochemically-active substances in natural antioxidants. Twelve kinds of crude drugs, which had been reported to exhibit strong activity in an antioxidative test based on the air oxidation of linoleic acid, were studied. The oxidative capacity calculated from voltammograms of their methanol extracts were compared and examined together with data on their radical scavenging effects. The results showed that the electrochemical behavior in most cases correlated with the radical scavenging effect. Crude drugs which had clear oxidative peaks below +1.2 V and a large oxidative capacity were suggested to have strong radical scavenging effects. It was clear that substances oxidized at lower potentials had stronger radical scavenging effects than those oxidized at higher potentials. Therefore, this electrochemical method can be considered as a rapid and simple method for estimating the antioxidative effects as a radical scavenger.

BACKGROUND: Angiotensin I-converting enzyme (ACE) is a dipeptidyl carboxypeptidase associated with the regulation of blood pressure. ACE inhibition results in a lowering of blood pressure. Lactic acid bacteria are known to produce ACE inhibitors during fermentation. Fermented camel milk is the main traditionally fermented dairy food for desert nomads. The beneficial effects of fermented camel milk, which include the prevention of such diseases and conditions as gastroenteritis, tuberculosis and hypertension, have been demonstrated experimentally. RESULTS: ACE inhibitory activity was observed in fermented milk containing Lactobacillus helveticus 130B4, a strain isolated from traditionally fermented camel milk. The peptide that inhibited ACE was purified from the fermented milk by reverse-phase high-performance liquid chromatography. The amino acid sequence of the peptide was identified as Ala-Ile-Pro-Pro-Lys-Lys-Asn-Gln-Asp (IC 50 = 19.9 µmol L −1 ). The same Ala-Ile-Pro-Pro-Lys-Lys-Asn-Gln-Asp sequence was found in κ-casein (κ-CN) f107-115 from milk. The inhibitory activity of this nonapeptide (κ-CN f107-115) was almost preserved even after successive digestion with pepsin, trypsin and chymotrypsin. Furthermore, the inhibitory activity of the purified peptide was completely preserved after heat treatment at 100 • C for 20 min.CONCLUSION: The fermented milk prepared with Lactobacillus helveticus 130B4 contained an ACE inhibitory peptide, κ-CN 107-115. This fermented milk was expected to have anti-hypertensive effect after ingestion because the peptide was stable to digestive protease and heat treatment in vitro.

Introducing exogenous genes into plant cells is essential for a wide range of applications in agriculture and plant biotechnology fields. Cationic peptide carriers with cell-penetrating and DNA-binding domains successfully deliver exogenous genes into plants. However, their cell-penetrating activity may be attenuated by undesired electrostatic interactions between the cell-penetrating peptide (CPP) domain and DNA cargo, resulting in limited gene delivery efficiency. Here, we developed the block copolymer maleimide-conjugated tetra(ethylene glycol) and poly(L-lysine) (MAL-TEG-PLL). Through electrostatic interactions with plasmid DNA (pDNA), MAL-TEG-PLL formed a micelle that presented maleimide groups on its surface. The micelle enabled postmodification with cysteine-containing functional peptides, including a CPP (BP100-Cys) and nuclear localization signal (Cys-NLS) via thiol−maleimide conjugation, thereby avoiding undesired interactions. According to a comparison of gene delivery efficiencies among the peptide-postmodified micelles, the amount of BP100-Cys on the micelle surface was key for efficient gene delivery. The BP100-postmodified micelle showed more efficient delivery compared with that of the BP100-premodified micelle. Thus, postmodification of polymeric micelles with functional peptides opens the door to designing highly efficient plant gene delivery systems.

Three domain-swapped cytochrome cb 562 dimers formed a unique cage structure with a Zn–SO4 cluster inside the cavity.

The delivery of DNA to plants is crucial for enhancing their ability to produce valuable compounds and adapt to climate change. Peptides can provide a versatile tool for delivering DNA...

We isolated a total of 266 strains of lactic acid bacteria (LAB) from 28 dahi samples that were collected from different areas in Bangladesh. The isolated strains were identified on basis of their morphological, physiological and biochemical characteristics, the lactic acid isomer produced, the ability to ferment sugars and 16S rDNA analysis. Among the isolates, the cocci (73%) were dominant over the rods (27%). The distribution of the isolates by genus was as follows: Streptococcus (50%), Lactobacillus (27%), Enterococcus (9%), Leuconostoc (5%), Lactococcus (5%) and Pediococcus (4%). In this study, S. bovis was the most predominant species as this species represents 47.0% of the total isolates in dahi. The other species we isolated were identified as Lb. fermentum, Lb. delbrueckii ssp. bulgaricus, Lb. delbrueckii ssp. lactis, Lb. sp., Ec. faecium, S. thermophilus, Leuc. mesenteroides ssp. mesenteroides, Leuc. mesenteroides ssp. dextranicum, Lc. lactis ssp. lactis, Lc. raffinolactis and P. pentosaceus.

Owing to their diverse functions and tunable physicochemical properties, peptides are promising alternatives to the conventional gene delivery tools that are available for plant systems. However, peptide-mediated gene delivery is limited by low transfection efficiency in plants because of the insufficient cytosolic translocation of DNA cargo. Here, we report a dual peptide-based gene delivery system for the efficient transfection of plant callus cells. This system is based on the combination of an artificial peptide composed of cationic cell-penetrating and hydrophobic endosomal escape domains with a gene carrier peptide composed of amphiphilic cell-penetrating and cationic DNA-binding domains. Cellular internalization and transfection studies revealed that this dual peptide-based system enables more efficient transfection of callus cells than does a carrier peptide alone by enhancing the endocytic uptake and subsequent cytosolic translocation of a carrier peptide/DNA complex. The present strategy will expand the utility of peptide-mediated plant gene delivery for a wide range of applications and basic research.