Autochthonous halotolerant plant growth-promoting rhizobacteria promote bacoside A yield of Bacopa monnieri (L.) Nash and phytoextraction of salt-affected soil

Phytoremediation is a promising approach for reclamation of salt-affected soil. Phytoextraction is the most commonly used process, which exploits plants to absorb, immobilize, and accumulate salt in their shoots. In this study, halotolerant plant growth-promoting rhizobacteria (PGPR) were isolated from the rhizosphere of wild grasses growing naturally in salt-affected areas of Lucknow, Uttar Pradesh (India) and were tested for their efficacies of salt-tolerance and plant growth-promoting (PGP) abilities. Based on 16S rRNA sequences, the most efficient halotolerant isolates possessing PGP traits were identified as Pseudomonas plecoglossicida (KM233646), Acinetobacter calcoaceticus (KM233647), Bacillus flexus (KM233648), and Bacillus safensis (KM233652). Application of these isolates as bio-inoculants significantly (P < 0.05) increased the growth and bacoside A yield of a medicinal plant, Bacopa monnieri (L.) Nash, grown on natural salt-affected soil. The phytoremediation of salt-affected soil was evident by the substantial increase in shoot Na⁺:K⁺ ratio of bio-inoculant-treated plants. When compared to un-inoculated control plants, the soil physico-chemical properties of bio-inoculant-treated plants were improved. The shoot and root biomass (fresh and dry weights), soil enzymes, and soil nutrient parameters showed significant positive correlations with the shoot Na⁺:K⁺ ratio. Consequently, the halotolerant PGPR screened in this study could be useful for the reclamation of saline soils concomitant with improved plant growth and bacoside A yield.     

Bacterial communities associated with natural and commercially grown rooibos (Aspalathus linearis)

Aspalathus linearis is a commercially important plant species endemic to the Cape Floristic Region of South Africa and is used to produce a herbal tea known as rooibos tea. Symbiotic interactions between A. linearis and soil bacteria play an important role in the survival of Aspalathus plants in the highly nutrient-poor, acidic fynbos soil. The aim of this study was to characterize and compare rhizosphere and bulk soil bacterial communities associated with natural and commercially grown A. linearis, as well as the effect of seasonal changes on these communities. Bacterial communities were characterized using high throughput amplicon sequencing, and their correlations with soil chemical properties were investigated. The N-fixing bacterial community was characterized using terminal restriction fragment length polymorphism and real time quantitative polymerase chain reaction. Actinobacteria, Proteobacteria, and Acidobacteria were the most dominant bacterial phyla detected in this study. Highly similar bacterial communities were associated with natural and commercially grown plants. Significant differences in the bacterial community were observed between rhizosphere and bulk soils collected in the dry season, while no significant differences were detected in the wet season. This study provides insights into bacterial community structure and potential factors shaping bacterial community structure with commercially important A. linearis.     

Biochemical and morphological risk assessment of transgenic wheat with enhanced iron and zinc bioaccessibility

Decreased iron and zinc bioaccessibility, caused by the anti-nutrient phytic acid, is one of the leading reasons for micronutrient deficiency-related disorders. Biofortification of wheat with phytase gene to enhance iron and zinc bioaccessibility appears to be a fitting solution for this problem, especially in developing countries where most of the population belongs to the lower economic sector. However, societal views on crops, particularly crops that are genetically modified (GM) to express a new trait, needs to be changed. Risk assessment of GM crops can play a crucial role in fostering positive public perception, since it is imperative to ensure safety before allowing human consumption. The present study performed compositional and morphological risk assessment of T3 and T4 generations of phytase transgenic wheat by comparing their biochemical and morphological traits. Transgenic plants were analysed for their carbohydrate, protein, starch and phytic acid content along with iron bioaccessibility, zinc bioaccessibility and phytase enzyme activity. Morphological traits studied included plant height, seed number, seed weight and spike number. No significant differences were observed for carbohydrate, protein, starch content and for morphological traits; however, a significant increase was observed in phytase activity as well as iron and zinc bioaccessibility, which correlated with a significant decrease in phytic acid. These results demonstrate that phytase transgenic wheat is as native as local wheat varieties and can potentially increase iron and zinc bioaccessibility.     

Validation of an extraction method for the quantification of soluble free and insoluble bound phenolic compounds in wheat by HPLC-DAD

Wheat is one of the three most widely grown grain crops and the most consumed in Europe. Wheat contains different phenolic compounds, mainly phenolic acids and flavonoids that are not evenly distributed in the wheat, being most abundant in the bran. These phenolic compounds are antioxidants against free radicals and other reactive oxygen species. Therefore, over the last few decades, there is a great interest to study and quantify these compounds present in wheat.This work proposes a HPLC-DAD method that allows a good separation of different phenolic compounds occurring as soluble free and insoluble bound compounds in wheat brand and flour. The extraction and the chromatographic conditions allowed the characterization of forty-two phenolic compounds, among phenolic acids (HBA, HCA, DFA and TFA), phenolic aldehydes, phenolic alcohols and flavonoids (flavones). This method is simple, sensitive, reproducible and accurate, and only a HPLC-DAD equipment is required. Thirty-four soluble and insoluble phenolic compounds can be quantified in wheat flour and brand. Hydroxytyrosol, a potent antioxidant compound, has been identified and quantified in wheat for the first time.     

Effects of Different Factors on Concentration of Functional Components of Aronia and Saskatoon Berries

Plant Foods for Human Nutrition - Effects of different factors on the content of phenolics, anthocyanins, antioxidants and colour parameters in two varieties of Aronia and three varieties of...     

Comparison of Chemical Composition and Biological Properties of Essential Oils Obtained by Hydrodistillation and Steam Distillation of Laurus nobilis L.

Plant Foods for Human Nutrition - The purpose of this study was to compare the yield, chemical composition, antimicrobial and antioxidant properties of essential oils isolated from leaves of Laurus...     

Kernel vitreousness and protein content: Relationship,interaction and synergistic effects on durum wheat quality

Four sets of durum samples were used in this study to further understand the interrelationships among hard vitreous kernels (HVK), protein content, and pigment concentration, with a focus on the interaction and synergistic effects of protein content and vitreousness on durum quality. HVK level increases with higher protein content in the range of 9.5–12.5%, but this relationship is less evident in durum samples with high protein content (12.5–14.5%). Both protein content and kernel vitreousness can significantly affect durum milling quality. White starchy kernels (WSK) in low protein durum have a very detrimental impact on milling and pasta processing quality, but high protein content can mitigate the adverse impact of WSK on durum quality. Although protein content plays a dominant role, higher HVK might contribute positively to pasta firmness. There was no significant difference in yellow pigment content between HVK and WSK. However, pigment loss from semolina to dough was higher for WSK than HVK. Despite the difference in protein content, HVK and WSK have little difference in gluten strength. The monomeric protein was preferentially accumulated in HVK. The glutenin proteins of HVK and WSK were similar in the ratios of 1Bx/1By and HMW/LMW-GS.     

Aquaponics and sustainability: The comparison of two different aquaponic techniques using the Life Cycle Assessment (LCA)

Aquaponics is generally regarded as a sustainable practice, but its environmental burdens were not yet deeply investigated. In this study, Life Cycle Assessment (LCA) was used to assess the environmental impacts of two hypothetical coupled aquaponics systems (CAPS): Raft System (RAFT) and Media-Filled Beds System (MFBS). Rainbow trout (Oncorhynchus mykiss) and lettuce (Lactuca sativa) were considered as cultivated species in both systems. The Simapro^© software V.8.0 was used for calculation. The comparison between the two virtual systems indicated the floating technique as the less impacting one. Even though energy consumption appears to be higher in the floating system, LCA results were markedly influenced by the extensive use of inert materials in MFSB. In both systems, contribution analyses underlined that the main environmental impacts are related to infrastructures, electricity and fish feed. The LCA analyses carried out in this study highlights that the choice of less impacting materials, and the optimization of management practices, should be taken as priorities in order to reduce environmental impacts of this activity.