Lignin, the earth’s second-most abundant biopolymer after cellulose, has long been relegated to low-value byproducts in the pulp and paper industry. However, recent advancements in valorization are transforming lignin into a sustainable and versatile feedstock for producing high-value biofuels, bioplastics, and specialty chemicals. This review explores the conversion of lignin’s complex structure, composed of syringyl (S), guaiacyl (G), and p-hydroxyphenyl (H) units, into value-added products. We critically assess various biochemical and analytical techniques employed for comprehensive lignin characterization. Additionally, we explore strategies for lignin upgrading and functionalization to enhance its suitability for advanced biomaterials. The review emphasizes key areas of lignin valorization, including catalytic depolymerization methods, along with the associated challenges and advancements. We discuss its potential as a feedstock for diverse products such as biofuels, bioplastics, carbon fibers, adhesives, and phenolic compounds. Furthermore, the review briefly explores lignin’s inherent properties as a UV protectant and antioxidant, alongside its potential for incorporation into polymer blends and composites. By presenting recent advancements and case studies from the literature, this review highlights the significant economic and environmental benefits of lignin valorization, including waste reduction, lower greenhouse gas emissions, and decreased reliance on non-renewable resources. Finally, we address future perspectives and challenges associated with achieving large-scale, techno-economically feasible, and environmentally sustainable lignin valorization.

The plant biomass and agro-industrial wastes show great potential for their use as attractive low cost substrates in biotechnological processes. Wheat straw and corn cob as hemicellulosic substrates were acid hydrolyzed and enzymatically saccharified for high xylose production. The hydrolysate was concentrated and fermented by using Saccharomyces cerevisiae and Kluyveromyces for production of xylitol. Acid hydrolysis of wheat straw and corn cob in combination with enzymatic hydrolysis showed great potential for production of free sugars from these substrates. Kluyveromyces produced maximum xylitol from acid treated wheat straw residues with enzymatic saccharification. The percentage xylitol yield was 89.807 g/L and volumetric productivity of 0.019 g/L/h. Kluyveromyces also produced maximum xylitol from corn cob acid hydrolyzed liquor with xylitol yield 87.716 g/L and volumetric productivity 0.018 g/L/h. Plant and agro-industrial biomass can be used as a carbohydrate source for the production of xylitol and ethanol after microbial fermentation. This study revealed that wheat straw acid and enzyme hydrolyzed residue proved to be best raw material for production of xylitol with S. cerevisiae. The xylitol produced can be utilized in pharmaceuticals after purification on industrial scale as pharmaceutical purposes.

Hearing loss is a genetically heterogeneous disorder affecting approximately 360 million people worldwide and is among the most common sensorineural disorders. Here, we report a genetic analysis of seven large consanguineous families segregating prelingual sensorineural hearing loss. Whole-exome sequencing (WES) revealed seven different pathogenic variants segregating with hearing loss in these families, three novel variants (c.1204G>A, c.322G>T, and c.5587C>T) in TMPRSS3, ESRRB, and OTOF, and four previously reported variants (c.208C>T, c.6371G>A, c.226G>A, and c.494C>T) in LRTOMT, MYO15A, KCNE1, and LHFPL5, respectively. All identified variants had very low frequencies in the control databases and were predicted to have pathogenic effects on the encoded proteins. In addition to being familial, we also found intersibship locus heterogeneity in the evaluated families. The known pathogenic c.226C>T variant identified in KCNE1 only segregates with the hearing loss phenotype in a subset of affected members of the family GCNF21. This study further highlights the challenges of identifying disease-causing variants for highly heterogeneous disorders and reports the identification of three novel and four previously reported variants in seven known deafness genes.

Hereditary spastic paraplegias are a diverse group of degenerative disorders that are clinically categorized as isolated; with involvement of lower limb spasticity, or symptomatic, where spastic paraplegia is complicated by further neurological features. We sought to identify the underlying genetic causes of these disorders in the participating patients. Three consanguineous families with multiple affected members were identified by visiting special schools in the Punjab Province. DNA was extracted from blood samples of the participants. Exome sequencing was performed for selected patients from the three families, and the data were filtered to identify rare homozygous variants. ExomeDepth was used for the delineation of the copy number variants. All patients had varying degrees of intellectual disabilities, poor speech development, spasticity, a wide-based gait or an inability to walk and hypertonia. In family RDHR07, a homozygous deletion involving multiple exons and introns of SPG11 (NC000015.9:g.44894055_449028del) was found and correlated with the phenotype of the patients who had spasticity and other complex movement disorders, but not those who exhibited ataxic or indeterminate symptoms as well. In families ANMD03 and RDFA06, a nonsense variant, c.985C > T;(p.Arg329Ter) in DDHD2 and a frameshift insertion‒deletion variant of AP4B1, c.965-967delACTinsC;p.(Tyr322SerfsTer14), were identified which were homozygous in the patients while the obligate carriers in the respective pedigrees were heterozygous. All variants were ultra-rare with none, or very few carriers identified in the public databases. The three loss of function variants are likely to cause nonsense-mediated decay of the respective transcripts. Our research adds to the genetic variability associated with the SPG11 and AP4B1 variants and emphasizes the genetic heterogeneity of hereditary spastic paraplegia.

Ataxia–telangiectasia (A–T) is a heterogeneous genetic disorder with a recessive mode of inheritance resulting from biallelic variants in the A–T mutated gene (ATM). Besides ataxia, the disorder involves compromised immunity and an increased risk of malignancies. We recruited a consanguineous Pakistani family with multiple individuals having adolescent‐onset ataxia. Phenotyping and clinical testing were completed for the patients. DNA samples from multiple individuals were used for bidirectional exome sequencing at 100X coverage, and data were aligned to the hg19 genome assembly. Sanger sequencing was completed to confirm the segregation of the variants. Multiple sequence alignments of orthologous proteins from diverse species were performed using ClustalO to check the amino acid conservation. Patients in the family manifested gait and limb ataxia, postural instability, and dystonia. A known heterozygous pathogenic nonsense ATM variant, c.2413C > T, p.(Arg805Ter), in trans with a new unreported missense variant, c.8708C > T, p.(Pro2903Leu), was identified, which segregated with the disease. The missense variant affected an amino acid, which was conserved in evolution. Telangiectasia of the eyes and skin was absent in the affected individuals, which led to the initial misdiagnosis of the disease as cerebellar ataxia. There were no reports of malignancies in the family, and affected individuals were alive in their third and fourth decades of life. Thus, molecular analyses resulted in the reclassification of the disease as A–T, an example of reverse phenotyping. The study expands the phenotypic heterogeneity of A–T and extends the allelic spectrum of ATM variants.

Bifenthrin is a synthetic pyrethroid insecticide. It is used worldwide against different agricultural pests. Nervous system (NS) is the primary target organ for the pyrethroid group of insecticide which causes hyper excitation. The aim of this study to determine the effects of bifenthrin on the brain of rabbits. The animals were treated for 14 days with three different doses (1/5th, 1/10th and 1/15th of LD50) of bifenthrin. Neurotransmitters and Histopathological alterations were observed at the end of the experiments. Neurochemical parameters were checked 24 hours after the last dose. Significant changes in the level of biogenic amines were observed. The levels of epinephrine (EPN), dopamine (DA), 3, 4 dihydroxyphenylacetic acid (DOPAC) were decreased as compared to controls group with the increase in insecticide. However, norepinephrine (NE) and homovanillic acid (HVA) levels were found to be significantly higher than those of the controls. A significant reduction in the activity of the acetyl cholinesterase enzyme was found in the frontal cortex’s erythrocyte, plasma and brain of rabbit with the increase in administered bifenthrin. The oxidative stress showed significantly decrease in the activity of glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT) and glutathione S- transferase (GST) with the increase in dose of bifenthrin. Histopathological study of brain tissues showed normal GC (glial cells) and NC (neuronal cells) in the frontal cortex of brain tissue of control groups while the treated groups showed evacuation (odema), elongation of pyramidal nucleus, glial cell damage and brain haemorrhage.