The use of biocatalysts such as enzymes has achieved a notable increase in the most varied industrial fields such as chemical, biochemical, pharmaceutical, medical, waste treatment, food and beverage, textile, pulp and paper, leather, biofuel, and animal feed (Mulinari et al., 2020). The interest is due not only to the possibility of improving the sustainability of a process (reduction of process time, low energy requirement, and non-toxicity) but also to the exceptional chemo-, regio- and enantio-selectivity of this kind of molecules. Furthermore, the development of recombinant DNA technology and bioengineering on unicellular life forms such as bacteria, fungi, and yeasts have given the possibility to further expand their applicability (Liu et al., 2013). As result, the total enzyme market was worth USD 9.9 billion in 2019 and the market for microbial lipases (triacylglycerol acyl hydrolases EC 3.1.1.3) is expected to grow by 7.1% in the next six years (Santos et al., 2021) reaching USD 590.2 million by 2023 (Chandra et al., 2020, Houde et al., 2004, Singh and Mukhopadhyay, 2012) thanks to their unique versatility and the fact that they can be easily and cheaply produced on large scale. Their role is to catalyze the hydrolysis of triglycerides into diglycerides, monoglycerides, and fatty acids but also a wide range of bioconversion reactions such as esterification, interesterification, aminolysis, and alcoholysis (Chandra et al., 2020, Rajendran et al., 2009). However, although the lipase-catalyzed processes have been extensively employed in different industrial fields (Chandra et al., 2020), their use is limited for the difficulty of recovery and reuse, long operational times, and low stability of the catalyst (F. L. C. Almeida et al. (2021)). These drawbacks can be overcome by immobilization techniques which are becoming a flourishing developing field in chemical research.

While using supports may seem like an additional cost, it can lead to many overall economic benefits and savings. Indeed, the possibility to confine an enzyme on a solid matrix by physical or chemical interactions produces better stability against heat, pH, and denaturing agents, preventing the loss of the enzyme during the procedures. Moreover, it can also provide higher precision in the catalytic process control and allows the use of a multi-enzymatic system when needed. The main advantage, however, is that the recovery of the enzyme permits its recycling for various processes.

In the immobilization process, carriers and methods affect the biocatalyst properties and stability by causing a general increase in the protein's structural rigidity and resistance to different environmental factors (Mokhtar et al., 2020). Carriers should have a large surface area, high rigidity, and suitable particle size and must be resistant to microbial attacks. For lipase immobilization, various types of carriers are employed: inorganic materials of different sizes (micro, meso, and nano) (Costantini and Califano, 2021, Meena et al., 2021), DNA nanostructures (Thangaraj and Solomon, 2019a), metal-organic frameworks (MOFs) (Shomal et al., 2022), and, obviously, natural or synthetic polymers (Ismail and Baek, 2020, Thangaraj and Solomon, 2019a). DNA technology is based on the programmability of DNA hybridization for complex biomolecular nanostructures synthesis (Arora and Silva, 2018). Although it reduces the mass transfer resistance by controlling the relative positions and directions of enzymes in a confined space, this promising technology can hardly meet the requirements of large-scale industrial applications for the operation difficulty and high cost in the current stage. MOFs are formed from metal ions and ligands via coordination bonds in a porous crystalline structure. The high porosity and large surface-to-volume ratio indicate that MOFs could be ideal supports, but long-term water stability and the potential leaching of toxic metal ions still need to be addressed, especially considering the concept of green production (Xu et al., 2020). Finally, natural and synthetic polymers are the most common materials used in this field. From a comparison, it appears that even if the synthetic polymers show greater mechanical strength and versatility since they are selected according to the needs of the enzyme and the process, they require expensive and lengthy syntheses. Contrarily, natural polymers, although they may lack mechanical strength, still improve well catalytic performance, and may be directly used without any complex pretreatment (Zdarta et al., 2018). Furthermore, biopolymers possess unique characteristics, from biodegradability, harmless products, biocompatibility, and non-toxicity to an outstanding affinity to proteins (Alnoch et al., 2020). For instance, polysaccharides, cellulose, chitosan, alginate, and their derivatives, besides being renewable and easy to obtain, present reactive functional groups in their structure, mainly hydroxyl but also amine and carbonyl moieties, enable direct reaction between the enzyme and matrix (Bezerra et al., 2015). Therefore, the current industrial interest in clean, selective, and low-cost processes has drawn scientific attention to the research of new renewable supports for lipase immobilization. In this context, in the last decade, the focus has been placed on natural lignocellulosic materials discarded from the agro-industrial production chain thanks to their physical and chemical characteristics and to the possibility of transforming wastes into a source of new added-value compounds (Girelli et al., 2020, Melchor-martínez et al., 2022). In this way, lignocellulosic biomass can promote sustainability and alleviate existing pollution by reducing the rate of waste disposal. Generally, these by-product materials, generated in a million tons annually, are derived from the processing of agro-industrial products, such as rice, sugarcane bagasse, wood cellulignin, corn, coconut, spent grains, etc.

So, considering the topicality of the subject, the focus of this review is on the scientific attention in the 2000–2021 years for the lipase immobilization on lignocellulosic waste. The authors' prospect is to provide state-of-the-art perspectives for the support choice and experimental assessment. The review intends to guide readers and give them a useful tool to select the methodology that best suits them.

The review intends to guide readers and give them the knowledge required to broaden enzymes’ application prospects in biotechnological processes that are still limited. It will present the various lignocellulosic wastes and the treatments required to use them as cheap and environmentally friendly supports. Furthermore, the immobilization conditions that are necessary to obtain an efficient solid biocatalyst from these carriers and an incredibly versatile enzyme (lipase) will be examined.