Development of halophytes as energy feedstock by applying genetic manipulations

Abstract

Decreasing arable land and fresh water resources, and increasing soil salinization and production of energy from food crops pose a threat to plant productivity and caused several environmental problems. Using plant species which can grow on saline degraded soils for energy production can be a sustainable approach because they do not compete for the agricultural lands and availability of fresh water. These plants can be cultivated with seawater without compromising their biomass for commercializing purposes such as lignocellulosic content and seed yields and could strongly benefit as energy plants. Optimizing biomass production and its economic conversion to the end product are, however, of paramount importance. The biomass of halophytes can be improved through studying unexplored aspects of these plants related to genetic manipulations. Here, we recommended current advances and highlight the key genetic approaches required in halophytes for biofuel production. Genetic approaches might lead to desired alterations in the composition of halophytic lignocellulosic biomass, including higher quantity of cellulose and hemicelluloses and lower lignin. In summary, the genetic manipulations in halophytes might lead to improvement in biomass compositions hence can be used as a feedstock for the production of biofuel on nutrient poor degraded soils.

Wild Halophytic Phragmites karka Biomass Saccharification by Bacterial Enzyme Cocktail

“…Panicum antidotale belongs to the family Poaceae found throughout tropical regions. It can resist salinity and drought conditions, is reported as a useful animal fodder ( Khan and Qaiser, 2006 ), and contains 28% cellulose, 27.97% hemicellulose, 9.1% ash, and 6% lignin ( Lima et al, 2019 ; Munir et al, 2020 ). A stoloniferous perennial grass, H. mucronatum , commonly grows in Asian and African peninsulas on high coastal dunes, has been widely reported for its heavy metal phytoremediation potential in polluted sites ( Mujeeb et al, 2020 ), and contains 38% cellulose, 28.67% hemicellulose, 2% ash, and 5% lignin ( Weber et al, 2007 ; Munir et al, 2020 ).…”

“…It can resist salinity and drought conditions, is reported as a useful animal fodder ( Khan and Qaiser, 2006 ), and contains 28% cellulose, 27.97% hemicellulose, 9.1% ash, and 6% lignin ( Lima et al, 2019 ; Munir et al, 2020 ). A stoloniferous perennial grass, H. mucronatum , commonly grows in Asian and African peninsulas on high coastal dunes, has been widely reported for its heavy metal phytoremediation potential in polluted sites ( Mujeeb et al, 2020 ), and contains 38% cellulose, 28.67% hemicellulose, 2% ash, and 5% lignin ( Weber et al, 2007 ; Munir et al, 2020 ). Another perennial grass, D. bipinnata , is composed of 26.67% cellulose, 24.68% hemicellulose, 12.87% ash, and 6.67% lignin ( Shah et al, 2017 ; Munir et al, 2020 ), is considered as sacred in India, and has been extensively studied for the isolation of medicinally important compounds and for pharmacological properties ( Guntur et al, 2018 ).…”

“…A stoloniferous perennial grass, H. mucronatum , commonly grows in Asian and African peninsulas on high coastal dunes, has been widely reported for its heavy metal phytoremediation potential in polluted sites ( Mujeeb et al, 2020 ), and contains 38% cellulose, 28.67% hemicellulose, 2% ash, and 5% lignin ( Weber et al, 2007 ; Munir et al, 2020 ). Another perennial grass, D. bipinnata , is composed of 26.67% cellulose, 24.68% hemicellulose, 12.87% ash, and 6.67% lignin ( Shah et al, 2017 ; Munir et al, 2020 ), is considered as sacred in India, and has been extensively studied for the isolation of medicinally important compounds and for pharmacological properties ( Guntur et al, 2018 ). P. karka is reported as the herbaceous woody culms that range from 4 to 10 m in length and 15–25 mm in diameter and is composed of 26% cellulose, 29% hemicellulose, and 10.33% lignin ( Munir et al, 2020 ) and 3.9–8.5% ash ( Eller et al, 2020 ).…”

“…Another perennial grass, D. bipinnata , is composed of 26.67% cellulose, 24.68% hemicellulose, 12.87% ash, and 6.67% lignin ( Shah et al, 2017 ; Munir et al, 2020 ), is considered as sacred in India, and has been extensively studied for the isolation of medicinally important compounds and for pharmacological properties ( Guntur et al, 2018 ). P. karka is reported as the herbaceous woody culms that range from 4 to 10 m in length and 15–25 mm in diameter and is composed of 26% cellulose, 29% hemicellulose, and 10.33% lignin ( Munir et al, 2020 ) and 3.9–8.5% ash ( Eller et al, 2020 ). Moreover, it can tolerate high ranges of salinity and flooding stress with enhanced growth rates ( Shoukat et al, 2020 ).…”

Assessment of quality and chemical composition of continental halophytic grasslands in south-east Europe

“…: 14.86%, and Carex ssp. :15% (Catling et al, 1994), Cynodon dactylon: 8.91% (Munir et al, 2020)). According to studies of Abou El Nasr et al (1996) and Badri and Ludidi (2020), where nutritional value of succulent plant parts in fresh or air-dried form was analysed, the silage is the most nutritious feed that can meet the energy and protein requirements of animals.…”