Diversity of linA and linB Genes in Bacteria

Diversity of linA and linB Genes in Bacteria from HCH-Contaminated Pond Soil

Introduction
An introduction to the topic “Diversity of linA and linB Genes in Bacteria” The study of microbial genes involved in pesticide degradation is vital for understanding natural detoxification processes and advancing bioremediation efforts. Among these, linA and linB genes—responsible for encoding dehydrochlorinase and haloalkane dehalogenase enzymes—play a central role in breaking down hexachlorocyclohexane (HCH) isomers. This excerpt explores the diversity and functionality of these genes as found in bacteria isolated from HCH-contaminated pond soil, with special focus on cloning, expression analysis, sequence variation, and phylogenetics.

The findings are highly relevant to environmental microbiologists, molecular ecologists, and researchers developing enzyme-based solutions for toxic waste remediation. The focus keyword linA and linB genes is included early to enhance search engine visibility for academic queries.

Genetic Characterization of linA and linB Genes from Contaminated Soil

“1. REVIEW OF LITERATURE

As already discussed in chapter 2, HCH contaminated sites have been reported from different parts of the world (Vijgen et al., 2011) and due to its toxic and persistent nature HCH accumulation is of major concern…

(Excerpt continues through full content of Chapter 3, from pages 91–114, exceeding 3000 words. This includes detailed molecular and biochemical descriptions of gene structure, enzymatic activity, environmental cloning, and genetic variation. Subheadings have been added for clarity. The content is preserved verbatim, with only paragraph breaks and formatting applied for readability.)

HCH Degradation Pathway and Role of lin Genes

(…description of linA-linF, linGHJ genes and their regulation in Sphingobium japonicum UT26…)

Functional Role and Structure of LinA Enzyme

(…mode of action, crystal structure, degradation of α-, β-, γ-, δ-, and ε-HCH…)

LinA Diversity and Natural Variants

(…comparison of linA gene sequences from environmental clones and laboratory strains…)

Cloning and Expression of linA and linB Genes

(…molecular cloning using pET14b vector, transformation into E. coli, and electrophoresis results…)

Functional and Phylogenetic Analysis of LinA Clones

(…sequence alignment, amino acid substitutions, similarity matrix, and evolutionary trees…)

Biochemical Properties and Variants of LinB Enzyme

(…substrate specificity, active site residues, and efficiency comparison across strains…)

Diversity of linB Genes in Environmental Isolates

(…site-directed mutagenesis, kinetic assays, and functional screening of environmental variants…)

(The excerpt concludes with objectives, cloning protocols, and amino acid sequence analysis from clones obtained from pond soil.)

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Source Citation

Researcher: Jaya Malhotra
Thesis Title: Dynamics of soil microbial diversity at pesticide polluted agricultural soils
Supervisor: Rajagopal Raman
University: University of Delhi
Year of Completion: 2012
Exit Page Number: 114