Graduate School
   
   
  

Insects for food: feed conversion efficiency, nutritional quality and fatty acid modification in the mealworm

Lab rotation project description

In order to manipulate the body insects to improve their nutrient composition we need to establish what is the body composition of the animal, particularly for those factors that are of nutrition significance, such as the types and quantities of PUFAs. In addition we wish to determine the insect’s capacity to modify its composition; for example does the insect express any of the fatty acid desaturases which can modify fatty acid profiles?   

Therefore this miniproject will harvest mealworms and extract their fat component to determine their percentage fat composition and, through our established HPLC techniques, their fatty acid profile at different stages of growth.  In addition we will seek to determine whether these insects expression 9-desaturase (also known as stearoyl CoA desaturase or SCD) which is responsible generation of MUFA in mammalian tissues.  To do this multiple cDNA alignment of SCD across species will be carried out which will allow the identification of common regions, thereby enabling the generation of PCR primers.  Using reverse-transcriptase PCR on total RNA extracted from mealworms a SCD cDNA sequence will be generated and confirmed by sequencing.  This can then be used to generate primers for quantitative RT-PCR which allow the level of SCD gene expression to be determined. 

This project will provide training in nutrient composition analysis, HPLC, sequence analysis, PCR and quantitative PCR.

Fact file

Research theme

Agricultural and Food Security

Location

Sutton Bonington Campus, University of Nottingham

Rotation

LR1, LR2, LR3

Contact

Simon Welham (Biosciences)

2nd supervisor

Prof Andy Salter (Biosciences)
Tim Parr (Biosciences)

BBSRC Doctoral Training Partnerships
 

Linked PhD Project Outline

Adequate provision of dietary protein to a burgeoning global population is increasingly challenging. There is an increasing demand for protein sources derived from livestock.  The capacity to meet this demand is compromised by the efficiency by which it can be achieved; limited land resource but perhaps more importantly the livestock production requirement of high quality feed sources which could be utilised for human nutrition.  These factors will impact on the nutrition of populations most in need of such a dietary protein source. Therefore in order to achieve Global Food Security, novel sources of nutrients for both human and livestock nutrition have to be identified. 
The production of insects, for either direct human consumption or as feed for other livestock, is a potential novel source of nutrients.  Insects are reported to have higher efficiencies of feed utilisation than production livestock  for example 1kg of liveweight gain is achieved by 1.7kg of feed in crickets and 2.5kg in chickens, with approximately 80%  and 55% of liveweight being edible. In addition, a distinct advantage of certain insect species is that they efficiently utilise vegetable waste matter, whereas to achieve efficient growth in monogastric species like poultry requires provision of human foods. Therefore the production of insects as a food source, either for humans or for the production of livestock, additionally enables the conversion of out-of-date food or from non-utilised plant material from crop harvesting into a functionally useful nutritional product.

In this project we will determine the extent to which insect production may be manipulated to maximise their feed efficiency and nutrient composition.  We have extensive experience in this area in livestock production systems which can be translated to insect production.  For example we are currently investigating the effect of adding exogenous enzymes, such as xylanase, which enhances the digestibility of plant based feeds and thereby feed efficiency and have experience in manipulating feed composition to enhance PUFA composition (both n-3 and CLA).    Mealworms are an example of insects that can be successfully maintained on vegetable waste and have been commercial utilised as a food source.  

Using mealwoms as a model system the aims of the project are

1. Establish the types of vegetable food waste which may be utilised as feed and the efficacy of their manipulation, for example with exogenous enzymes, by assessing population production (including determination of growth rates, fecundity and ultimate biomass generation).

2.   Determine the extent by which their nutrient composition can be manipulated by provision of nutrient enriched feed (e.g. with omega-3 PUFAs).  This will involve nutrient composition analysis and an exploration of the metabolic capacity of the insect to generate a body composition that is advantageous as a food source (for example their level of fatty acid desaturase activity).   

3. To assess the biological impact of these manipulations on nutrient composition through feeding trials in chickens.
Fit with BBSRC priorities: This project fits with BBSRC priorities in global food security and Industrial Biotechnology/Bioenergy as it seeks to develop and improve the production efficiency of novel nutrient source using the application of biotechnology (exogenous enzymes are developed by the biotech industry) .
 
 

The Graduate School

The University of Nottingham
A floor, Highfield House
University Park
Nottingham, NG7 2RD

Tel: +44 (0) 115 846 8400

Text: 07786209140 Email: graduate-school@nottingham.ac.uk