If we are not talking about physiological aspects,

evidences come either from elevation of enzyme concentration or depletion of the substrate..

any subsequences dependent on these will be supportive..e.g pH turned more acidic (for liberation of more Fatty acids by the lipase)...or even decreasing of oil viscosity because of hydrolysis.

Hello. As you said the optimum lipase was produced on 5th day. It means you extracted and assayed everyday from day 1 to onwards. ??

If not, then do the days optimization test first. So that one can conclude on which day maximum lipase produced. 

If yes, then there are many reasons for getting more production on 5th day like:

1. Growth: Growth of fungi is directly propertional to the production of enzyme. May be after 5th day there is a decline of growth of fungi.

2. pH: As Deyaa Abol Fotouh said pH has more influencing factor for enzyme production as it regulates the fungi growth too. 

3. substrates: Production will be more if the affinity of the microorganism towards the substrate is more. Therfore there will be a process of substrates tretment by alkali so that the substrates can be easily utilized by M.O. 

Hope it will help you. All the best.

Thanks for the response. Really appreciated. 

The extracted enzyme is the only lipase. Thanks for the attachment.

you can not extracted just enzyme ...mutienzyme extracted with lipase , but you can check it by the assay method .

Please see the attached paper.

https://www.researchgate.net/publication/285280401_Lipase_production_in_solid-state_fermentation_SSF_Recent_developments_and_biotechnological_applications

Best regards

I need a methodology for determining avicelase in solid state fermentation .... can anyone help me? - ResearchGate. Available from: https://www.researchgate.net/post/I_need_a_methodology_for_determining_avicelase_in_solid_state_fermentation_can_anyone_help_me#58a2c0c4ed99e1d531384fb6 [accessed Feb 14, 2017].

Article Lipase production in solid-state fermentation (SSF): Recent ...

For lipase assay I would like to advise to to follow winkler and stuckman 1979 methos as given in these papers.

https://www.researchgate.net/publication/47644372_Synthesis_of_ethyl_ferulate_in_organic_medium_using_Celite-immobilized_lipase

https://www.researchgate.net/publication/224900014_Catalytic_Potential_of_a_Nitrocellulose_Membrane-_Immobilized_Lipase_in_Aqueous_and_Organic_Media?ev=prf_pub

https://www.researchgate.net/publication/284078828_Cellulose_binding_domain_assisted_immobilization_of_lipase_GSlip-CBD_onto_cellulosic_nanogel_Characterization_and_application_in_organic_medium?ev=prf_pub

Hope it will help you.

Regards

Ashok

Article Synthesis of ethyl ferulate in organic medium using Celite-i...

Article Catalytic Potential of a Nitrocellulose Membrane- Immobilize...

Article Cellulose binding domain assisted immobilization of lipase (...