Professor  Simon  Cragg    School  of  Biological  Sciences,  University  of  Portsmouth,  UK  

Marine  wood  borers  in  biodegradation,  biotechnology  and  carbon  fluxes  

                                                             

Tuesday  March  31,  15:15,  Lecture  Hall,  Lovén  Centre  -­‐  Tjärnö  

 

Biodegradation  of  wood  in  the  sea  is  a  Portsmouth  speciality.  We  currently  focus  on  the  remarkable  digestive  processes  of  marine  wood-­‐boring  crustaceans  and  bivalves.  Very  few  animals  are  capable  of  exploiting  this  energy-­‐rich,  but  recalcitrant  substrate.  Understanding  this  capability  has  important  applications.  Firstly,  innovation  is  needed  in  wood  protection  in  the  marine  environment  as  established  methods  of  wood  protection  are  no  longer  permitted  in  marine  applications  due  to  environmental  concerns.  Rapid  evaluation  of  wood  protection  methods  requires  short-­‐duration  laboratory  testing  methods.  We  have  developed  methods  which  yield  statistically  robust  findings  within  a  matter  of  weeks,  rather  than  the  5  years  specified  in  the  relevant  European  Norm/British  Standard.  Secondly,  digestion  mechanisms  are  being  prospected  for  wood-­‐degrading  enzymes  that  can  be  used  in  biotechnological  processing  of  woody  biomass  to  yield  liquid  biofuel.  Genes  of  interest  have  been  identified  by  transcriptomic  exploration.  Candidate  genes  are  being  fed  into  an  experimental  pipeline  in  which  genes  are  expressed,  assayed  for  enzymatic  capability,  crystalized  and  diffracted  at  the  Diamond  Light  Source  synchrotron  to  reveal  protein  structure.  The  first  enzyme  structures  are  now  available.  These  give  precise  details  of  the  geometry  of  the  reaction  site  and  allow  for  molecular  dynamic  modelling  of  how  the  enzyme  flexes  in  solution.  This  information  is  already  being  used  to  evaluate  the  performance  of  these  enzymes  on  biotechnologically-­‐relevant  substrates.  The  third  application  of  our  understanding  of  the  borer  digestion  process  is  in  probing  the  mechanisms  underlying  wood-­‐related  carbon  fluxes.  These  fluxes  are  important  in  pristine  mangrove  ecosystems  and  represent  a  compelling  argument  for  restoring  ecosystems  where  forest  has  been  lost.  The  role  of  leaf  litter  has  been  well  characterised,  but  the  fate  of  other  half  of  primary  production  that  falls  as  woody  detritus  is  less  well  defined.  A  better  understanding  could  inform  carbon  trading  models  and  guide  ecosystem  restoration  efforts.