Sanjeet K. Verma

Phytoremediation using aromatic plants: a sustainable approach for remediation of heavy metals polluted sites.

C of soil and water bodies with toxic heavy metals has often resulted from human activities. Conventional technologies for treatment of heavy metals polluted soil require a huge capital cost. Use of aromatic plants rather than non aromatic edible crops for the treatment of heavy metals polluted land is a sustainable, aesthetic and environmental friendly technique. Here we discuss the benefits of using aromatic plants and risks related to non aromatic edible crops as suitable phytoremediation candidate. Heavy metals pollution of soil and water due to human induced activities poses a major threat to environmental sustainability. A significant proportion of the total geographical area has been and being polluted by heavy metals throughout the world. Heavy metals are the natural component of earth crust that cannot be degraded and destroyed but accumulate through food chain and cause potential human health risk and ecological disturbances. Among all the available technologies for the removal of heavy metals from polluted sites, phytoremediation is considered as an effective, low cost, environmental friendly and preferred cleanup option for contaminated areas. Plants through several natural, biophysical and biochemical processes, such as adsorption, transport and translocation, hyperaccumulation or transformation and mineralization, can remediate pollutants. Many plant species are able to grow under heavy metals polluted environments. These plants must have specific adaptations to survive there; they must be metallophytes, pseudometallophytes, or hyperaccumulators. Despite the fact of human health risk, several researchers investigated and recommended many edible crops for phytoremediation purposes. Recently, a Scopus (www.scopus. com) based survey of the literature for the period 1995−2009 was carried out by Vamerali et al. (2010) in order to take a census of crop species involved in phytoremediation research of heavy metals throughout the world. Authors reported that B. juncea (L.) an edible oil producing crop was the most cited (148 citations) among other eight studied crops such as Helianthus annuus (57 citations), B. napus, and Zea mays (both 39 citations). It clearly shows that a little concern is given to aromatic plants for the phytoremediation. But the problem of heavy metal contamination remains the same if we use edible crops for phytoremediation. These crops are being consumed by human or animals in one or the other forms. Ecologically, use of edible crops for phytoremediation is not viable because the heavy metals enter into food chain either consumption by human or animals. This clearly indicates that scientific community lacking a safe technology, in which health risk is negligible for the phytoremediation of heavy metal polluted sites. Aromatic plants are grown for the production of essential oils and food processing. The essential oil of aromatic plants is being used in soaps, detergents, insect repellents, cosmetic, perfumes, and food processing industries. These plants are nonedible and are not being consumed directly by humans or animal like cereals, pulses, vegetables. The essential oil from aromatic plants is free from the risk of heavy metals accumulation from plant biomass. The heavy metals do not enter the food chain through phytoremediation by aromatic plants. The wild animals do not damage/eat the aromatic crops due to its essence. In fact, aromatic plant resources are very abundant, and they can be used on large scale. These plants offer a novel option for their use in phytoremedation of heavy metal contaminated sites. Aromatic plants like vetiver (Vetiveria zizanioides), palmarosa (Cymbopogon martinii), lemon grass (Cymbopogon f lexuosus), citronella (Cymbopogon winterianus), geranium mint (Mentha sp.), tulsi (Ocimum basilicum) are ecologically feasible and viable. Some aromatic grasses like, lemon grass, palmarosa, citronella, vetiver, etc. are stress tolerant and perennial in nature. The herb can be collected in subsequent years for hydro distillation of essential oil. These crops have high valued with low input. Therefore, we propose here a safe, economically feasible and eco-friendly approach for phytoremediation using nonedible

Assessment of respiratory functions by spirometry and phrenic nerve studies in patients of amyotrophic lateral sclerosis

OBJECTIVE Spirometry is the most common test recommended to monitor respiratory dysfunction in patients of amyotrophic lateral sclerosis (ALS). However, the test depends on the patients efforts and may be difficult to conduct in patients with faciobulbar weakness. We aimed to study the role of phrenic nerve-electrophysiological studies to predict respiratory dysfunction and correlate it with the forced vital capacity (FVC) in patients of ALS. METHODS Forty-three unselected patients (32 male, 25 with limb-onset ALS, age 50±15 years) with clinically definite or probable ALS were included. They were evaluated at entry and after a period of 6 months with the ALS functional rating scale (ALSFRS), their respiratory subscores (ALS-FRSr), their FVC values as determined by spirometry, and phrenic nerve studies. RESULTS Six patients could not perform a satisfactory spirometry at the onset and during the course of illness. All the six patients had severe faciobulbar weakness. Respiratory abnormalities on spirometry were found in 85% of patients, whereas only 30% were symptomatic for respiratory dysfunction. In patients with severe respiratory dysfunction (FVC<60%), the phrenic nerve motor amplitudes (PNAMPs) were significantly reduced compared to those with mild-to-moderate respiratory dysfunction (FVC≥60%). The FVC value showed a significant correlation with the PN-AMP. Nine patients had a poor outcome (death or severe disability) at the end of a period of 6 months. Low levels of both FVC and PN-AMP were predictors of poor outcome for patients at the end of 6 months. CONCLUSION We conclude that respiratory dysfunction, as determined by spirometry, is common in patients of ALS. However, only about one-third of patients show symptoms of respiratory distress. Clinical symptoms of respiratory distress are unreliable predictors of respiratory failure in ALS. Measurement of PN-AMP at the time of presentation may be an additional tool to assess respiratory dysfunction in ALS. Reduced PN-AMP values may be indicative of low FVC and may have some role in the assessment of respiratory function in patients in whom a routine spirometry is not possible due to limitations arising from the illness. Both low FVC and reduced PN-AMP at the time of presentation are predictors of poor outcome for patients at the end of 6 months.

Temperature Relations for Seed Germination Potential and Seedling Vigor in Palmarosa (Cymbopogon martinii)

Because of non-synchronous flowering, fruiting, and dispersal of seeds, production and supply of quality seeds with well-defined germination potential parameters in Palmarosa are important issues for the growers. The objective of this study was to determine seed germination potential and seedling vigor of Palmarosa varieties under four temperature regimes at daily 16 h light/8 h dark regimes. At 25°C, germination percentage was highest for variety PRC-1 (67.8%), followed by varieties Tripta (59.3%), Trishna (57.5%), and Vaishnavi (35.5%). The mean for seedling vigor index I was highest for Trishna (277.7), followed by Tripta (259.3), PRC-1 (256.2), and Vaishnavi (140.4). However, vigor index II mean was highest for Tripta (0.2826), followed by PRC-1 (0.2615), Trishna (0.2600), and Vaishnavi (0.1388). Regardless of variety ranking by vigor index I vs. index II, the highest seedling vigor for all varieties was at 25°C using either index. However, since mass is a better indicator of seedling growth/health than length, vigor index II (based on mass) would give a better indication of early seedling vigor than index I (based on length). The low germination percentage and vigor of Vaishnavi is attributable to the genetic constitution of this self-pollinating variety. Significant decreases in germination percentage and vigor index I and II were observed at 20°C, 30°C, and 35°C. Days 2–3 and days 5–6 after sowing were the ideal times for making the first and final germination count, respectively. The study suggested that the Palmarosa nursery should have soil temperatures around 25°C with a day length of 16 h.

Improvement in the yield and quality of kalmegh (Andrographis paniculata Nees) under the sustainable production system

Andrographis paniculata Nees is an annual erect herb with wide medicinal and pharmacological applications due to the presence of andrographolide and other active chemical constituents. The large-scale cultivation of the kalmegh is not in practice. The aim of this study was to establish sustainable production systems of A. paniculata cv CIM-Megha with the application of different bioinoculants and chemical fertilisers. A. paniculata herb and andrographolide yield in the dried leaves was found to be highest (218% and 61.3%, respectively) in treatment T3 (NPK+Bacillus sp.) compared with T1 (control). The soil organic carbon, soil microbial respiration, soil enzymes activity and available nutrients improved significantly with combined application of bioinoculants and chemical fertilisers.

Aromatic Plant–Microbe Associations: A Sustainable Approach for Remediation of Polluted Soils

Plant–microbe association is a key driving factor for proper functioning of an ecosystem. Microbes are being popularly used to facilitate plant growth and agricultural productivity as they are actively involved in decomposition of organic matter, biogeochemical cycling, and soil structure formation. In spite of these functions, current empirical studies support the use of microbes for bioremediation (bioaccumulation, bio-transformation, volatilization, etc.) of various pollutants in our environment. As food crops cannot be recommended for cultivation on polluted sites due to potential risks of pollutants’ bioaccumulation, on the other hand, arable lands, cannot be utilized for cultivation of aromatic plants due to pressure of food demand. Hence, cultivation of aromatic crops on such contaminated sites will be a safe strategy as aromatic plants are stress-tolerant and their end product is essential oils, which are non-edible and remain free from pollutants. Reports suggest that the use of suitable plant–microbe association can be helpful in remediation of polluted sites as microbial secondary metabolites favor the plant growth, increase plant tolerance to pollutants, and also enhance the phytoextraction efficiency of plant by increasing the bioavailability of pollutants in rhizosphere. In this chapter, therefore, we review the available literature and discuss future perspectives on application of microbes in association with aromatic plants for remediation of heavy metal and xenobiotic polluted soils.