Acceptance of on-site wastewater treatment and reuse in Bengaluru, India: The role of perceived costs, risks, and benefits.

In dealing with water pollution and freshwater scarcity, on-site treatment and reuse of domestic wastewater has shown to be a promising solution. To increase on-site wastewater treatment and reuse, some cities, among them Bengaluru in India, have mandated the installation and use of the necessary technology in certain building types. However, even with a mandate, a successful and sustainable implementation of the technology, including reliable operation, monitoring, and maintenance, depends on the acceptance (i.e. positive valuation) of the technology and its use by the (prospective) users. Literature on technology acceptance indicates perceived costs, risks, and benefits of the respective technology as key predictors of acceptance. Therefore, the present online study assessed this relationship for on-site systems in Bengaluru. The relation was analysed separately for mandated users of on-site systems (N = 103) and current non-users (i.e. potential prospective users, should the mandate be expanded; N = 232), as the perceptions might differ between the two groups, due to the personal experience with the technology among users. The results show that for mandated users and non-users, acceptance of on-site systems is explained by perceived benefits only, namely a positive image of users, environmental benefits, and, only for non-users, also financial benefits for the city. The findings suggest that interventions aimed at promoting on-site systems should include emphasis on the benefits of on-site systems. Whenever possible, interventions should be tailored to the target group's individual cost, risk, and benefit perception.

Application of green synthesized bimetallic nZVI-Cu nanoparticle as a sustainable alternative to chemical fertilizers to enhance growth and photosynthetic efficiency of rice seedlings.

Application of nanomaterials in agriculture has been extensively explored over the past decade leading to a wide ambit of nanoparticle-based agrochemicals. Metallic nanoparticles consisting of plant macro- and micro-nutrients have been used as nutritional supplements for plants through soil amendments, foliar sprays, or seed treatment. However, most of these studies emphasize monometallic nanoparticles which limit the range of usage and effectivity of such nanoparticles (NPs). Hence, we have employed a bimetallic nanoparticle (BNP) consisting of two different micro-nutrients (Cu & Fe) in rice plants to test its efficacy in terms of growth and photosynthesis. Several experiments were designed to assess growth (root-shoot length, relative water content) and photosynthetic parameters (pigment content, relative expression of rbcS, rbcL & ChlGetc.). To determine whether the treatment induced any oxidative stress or structural anomalies within the plant cells, histochemical staining, anti-oxidant enzyme activities, FTIR, and SEM micrographs were undertaken. Results indicated that foliar application of 5 mg L-1 BNP increased vigor and photosynthetic efficiency whereas 10 mg L-1 concentration induced oxidative stress to some extent. Furthermore, the BNP treatment did not perturb the structural integrity of the exposed plant parts and also did not induce any cytotoxicity. Application of BNPs in agriculture has not been explored extensively to date and this study is one of the first reports that not only documents the effectivity of Cu-Fe BNP but also critically explores the safety of its usage on rice plants making it a useful lead to design new BNPs and explore their efficacy.

Genetic diversity assessment and biotechnological aspects in Aristolochia spp.

Aristolochia, belonging to the family Aristolochiaceae, has immense ecological significance due to its large size and huge geographic distribution. In the context of dealing with a genus with a huge number of species like Aristolochia, these markers come in handy to precisely identify a particular species and enumerate the genetic diversity. Also, certain species of Aristolochia are economically important due to the presence of secondary metabolites and vast use in traditional and modern medicine. But, the presence of profitable biochemical constituents in Aristolochia is very low and the breeding process of the plant is highly dependable on pollinators. Hence, identifying different biotechnological approaches to fasten the reproductive cycle of Aristolochia and increase the secondary metabolites is of great interest to the researchers. In this study, a comprehensive review has been established on different types of morphological/anatomical markers (starch grains with "Maltese cross"), phytochemical markers (aristolochic acid, triterpenoid, aristolactam etc.) and genetic markers (ISSR, SSR, DNA bar-coding) for various Aristolochia spp. We have also discussed the applications of different biotechnological tools in Aristolochia spp. which include discrete approaches to promote in vitro germination, in vitro shooting, root induction, somatic embryogenesis, synthetic seed production, acclimatization and hardening and sustainable production of secondary metabolites. In a nutshell, the present review is a first of kind approach to comprehensively demonstrate the genetic diversity studies and biotechnological aspects in Aristolochia spp. KEY POINTS: • Insights into the in vitro propagation of Aristolochia spp. • In vitro production and optimization of secondary metabolites. • Assessment of genetic diversity by molecular markers.

Biotechnology of camptothecin production in Nothapodytes nimmoniana, Ophiorrhiza sp. and Camptotheca acuminata.

Cancer is probably the deadliest human disease in recent years. In the past few years, rapid clinical progress has been made in the field of anticancer drug development. Plant secondary metabolites have been noted as extremely efficacious as promising natural source for anticancer therapy for many years. Camptothecin (CPT) is one of the popularly used anti-tumor drugs possessing clinically proven properties against a plethora of human malignancies that include ovarian and colorectal cancers. For the first time, CPT was obtained from the extracts of a Chinese medicinal tree, Camptotheca acuminata Decne. from the family Cornaceae. Subsequently, CPT was also isolated from the bark of Nothapodytes foetida (Wight) Sleumer (Icacinaceae). However, the availability of enough natural sources for obtaining CPT is a major constraint. Due to overexploitation and harvesting, loss of habitat, excessive trading, and unfavorable environmental factors, the natural source of CPT has become extinct or extremely limited and hence they are red listed under endangered species. Conventional propagation has also failed to meet the ever-expanding demand for CPT production. With this, biotechnological toolkits have constantly been used as a boon to produce sustainable source, utilization, and ex situ conservation of medicinal plants. The approaches serve as a supplement to traditional agriculture in the mass production of plant metabolites with potent bioactivities. Non-availability of enough anticancer medicine and the requirement to satisfy current demands need a sustainable source of CPT. With this background, we present a comprehensive review on CPT discovery, its occurrence in the plant kingdom, biosynthesis, phytochemistry, pharmacological properties, clinical studies, patterns of CPT accumulation, and biotechnological aspects of CPT production in three plants, viz., N. nimmoniana, Ophiorrhiza species, and C. acuminata.Key points• Biotechnological approaches on production of camptothecin from Nothapodytes nimmoniana, Ophiorrhiza species, and Camptotheca acuminata• In vitro propagation of camptothecin-producing plants• Genetic diversity and transgenic research on camptothecin-producing plants.