This review critically examines the entire value chain of microalgal biorefineries, with the central aim of elucidating the key technological, economic, and environmental enablers and barriers that govern their transition from pilot-scale demonstrations to commercially viable, circular-economy applications. A systematic literature search was conducted across five major scientific databases using predefined Boolean strings: "algal biorefineries," "microalgae biofuel," "techno-economic analysis," "life-cycle assessment," and "bioproduct recovery." Inclusion criteria encompassed peer-reviewed studies and authoritative policy documents published between January 2007 and March 2025 that provided empirical data on upstream cultivation, midstream processing, and downstream conversion, as well as techno-economic assessments (TEA) and life-cycle analyses (LCA). Exclusion criteria included non-English commentaries, purely theoretical models without experimental validation, and studies that focused exclusively on single-product streams. Unlike previous reviews that address isolated segments of the algal biorefinery pipeline, this work delivers a novel, integrative framework that synthesizes recent advances across cultivation modes, genetic and metabolic engineering, AI-enabled optimization, and IoT-driven monitoring. This review critically evaluates the trade-offs between CAPEX and OPEX, energy penalties associated with harvesting and drying, and inconsistencies in LCA to identify, where performance improvements yield the most significant economic and environmental returns. Finally, this review proposes a targeted research roadmap, spanning multivariate strain engineering, hybrid cultivation architectures, low-energy harvesting technologies, cascade-compatible fractionation platforms, standardized LCA/TEA protocols, and supportive policy mechanisms, that charts a clear path toward overcoming current bottlenecks. This comprehensive, evidence-based synthesis aims to inform both academic research and industrial strategy, thereby advancing the field of sustainable algal biorefineries.

Sugarcane (Saccharum officinarum) is one of the major crops cultivated in tropical and sub-tropical countries, and the primary purpose is to obtain raw sugar. It is an important substance for sugar and alcohol production by both the sugar and beverage industries. During cane processing, various byproducts are obtained, namely sugarcane bagasse, bagasse ash, pressmud cake, sugarcane vinasse, and spent wash. There are many challenging problems in storage, and they cause great environmental pollution. This review discusses their properties by which they can be used for cleaner agricultural and environmental sustainability. Utilization of byproducts results in value-added soil properties and crop yield. Replacing chemical fertilization with these organic natured byproducts not only minimizes the surplus usage of chemical fertilizers but is also cost-effective and an eco-friendly approach. The drawbacks of the long-term application of these byproducts in the agricultural ecosystem are not well documented. We conclude that the agriculture sector can dispose of sugar industry byproducts, but proper systematic disposal is needed. The need arises to arrange some seminars, meetings, and training to make the farming community aware of byproducts utilization and setting a friendly relationship between the farming community and industrialists.

Globally, the rapid rise in the human population has increased the crop production, resulting in increased pesticide xenobiotics. Despite the fact that pesticide xenobiotics toxify the soil environment and ecosystem, synthetic pesticides have increased agricultural yields and reduced disease vectors. Pesticide use has increased, resulting in an increase in environmental pollution. Various methods of controlling and eliminating these contaminants have been proposed to address this issue. Pesticide impurity in the climate presents a genuine danger to individuals and other oceanic and earthly life. If not controlled, the pollution can prompt difficult issues for the climate. Some viable and cost-effective alternative approaches are needed to maintain this emission level at a low level. Phytoremediation and microbial remediation are effective methods for removing acaricide scrapings from the atmosphere using plants and organisms. This review gives an overview of different types of xenobiotics, how they get into the environment, and how the remediation of pesticides has progressed. It focuses on simple procedures that can be used in many countries. In addition, we have talked about the benefits and drawbacks of natural remediation methods.

Two pot experiments were conducted to evaluate the response of radish crops against different plant growth regulators, biostimulants, and leaf extracts at Yale University, USA. The first experiment examined the marginal effect of vitamin B12 when added to the Berlyn Laboratory’s proprietary biostimulant formula (GPB Core). Increasing concentrations of vitamin B12 were added, as investigated in groups SL (0 mg/L), SB1 (0.5 mg/L), SB2 (1.0 mg/L), and SB3 (1.5 mg/L). The addition of vitamin B12 conferred no significant incremental benefit over the GPB Core. However, the GPB Core formula (SL) increased fresh shoot biomass by 172.9%, dry shoot biomass by 136.4%, fresh root biomass by 64.7%, and dry root biomass by 29.1% over plant treated with inorganic fertilizer alone (p < 0.01). The second experiment examined the combined marginal effect of vitamin B12 and coenzyme Q10 (CoQ10) when added to the GPB Core. The three experimental groups included the GPB Core plus inorganic fertilizer (S+); GPB Core, vitamin B12, CoQ10, and inorganic fertilizer (SBQ+); and GPB Core, vitamin B12, CoQ10, and no inorganic fertilizer (SBQ0). SBQ0 outperformed the inorganic fertilizer control in fresh shoot, dry shoot, fresh root, and dry root biomass by 190.3%, 127.1%, 128.5%, and 41.3%, respectively (p < 0.01), indicating that inorganic fertilizer can be replaced by biostimulants while simultaneously increasing yield. Additionally, the differences between SBQ+ and SBQ0 in the biomass metrics were statistically insignificant, indicating that in the presence of biostimulants, inorganic fertilizers confer a slight marginal benefit. There was no evidence, however, that the addition of CoQ10 and vitamin B12 conferred benefits over S+. Overall, the application of biostimulants statistically significantly improves radish biomass. Both experiments indicate that under low stress conditions, biostimulants can replace inorganic fertilizer while simultaneously increasing yield.

Plant growth stimulators (growth regulators + biostimulants; PGS) are chemical substances (organic/inorganic), helpful in plant growth and development. These are not considered as the replacement of fertilizers but can help in improved crop and soil quality. Both compounds can amplify the root biomass, nutrients translocation, enzymatic activities, crop yield, physiology, and nutrient uptake. Biostimulants are rich in minerals, vitamins, plant hormones, oligosaccharides, and amino acids. These compounds have a serious role to improve soil health, fertility, sorption, and desorption of nutrients. Hence, have a vital character in nutrients cycling, abiotic stress control, heavy metals bioavailability, and greenhouse gaseous emission. This chapter focuses on the discussions about the influence of plant growth regulators and biostimulants in crop production, soil health, heavy metal cycling, greenhouse gases emission with environmental sustainability. Whereas, the impact of biostimulants on greenhouse gases is a research gap.

An ever-increasing population has issued an open challenge to the agricultural sector to provide enough food in a sustainable manner. The upsurge in chemical fertilizers to enhance food production had resulted in environmental problems. The objective of the current study is to assess the utilization of biostimulants for sustainable agricultural production as an alternative to chemical fertilization. For this purpose, two pot experiments were conducted to examine the response of radish against individual and combined applications of biostimulants. In the first experiment, the effects of chemical fertilizer (CK), glycine (G), lysine (L), aspartic acid (A), and vitamin B complex (V) were studied. The results demonstrated that V significantly improved the transpiration rate (81.79%), stomatal conductance (179.17%), fresh weight (478.31%), and moisture content (2.50%). In the second experiment, tested treatments included chemical fertilizer (CK), Isabion^® (I), glycine + lysine + aspartic acid (GLA), moringa leaf extract + GLA (M1), 25% NPK + M1 (M2). The doses of biostimulants were 5g L⁻¹ glycine, 1g L⁻¹ lysine, 2g L⁻¹ aspartic acid, and 10 ml L⁻¹ moringa leaf extract. The photosynthetic rate improved significantly with GLA (327.01%), M1 (219.60%), and M2 (22.16%), while the transpiration rate was enhanced with GLA (53.14%) and M2 (17.86%) compared to the Ck. In addition, M1 increased the stomatal conductance (54.84%), internal CO₂ concentration (0.83%), plant fresh weight (201.81%), and dry weight (101.46%) as compared to CK. This study concludes that biostimulants can effectively contribute to the sustainable cultivation of radish with better growth and yield.